RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: Sekar started a business investing Rs.25,000 in 1999. In 2000, he invested an additional amount of Rs.10,000 and Rajeev joined him with an amount of Rs.35,000. In 2001, Sekar invested another additional amount of Rs.10,000 and Jatin joined them with an amount of Rs.35,000. What will be Rajeev's share in the profit of Rs.1,20,000 earned at the end of 3 years from the start of the business in 1999?
A.Rs.40,000
B.Rs.50,000
C.Rs.70,000
D.Rs.75,000
Answer: A.Rs.40,000
Explanation: Solution
Sekar:Rajeev:Jatin=	(25000×12+35000×12+45000×12):(35000×24) : (35000×12)
= 1260000 : 840000 : 420000
= 3 : 2 : 1.
Rajeev's share	=Rs.(120000×2/6)
= Rs.40000.
Answer A
Question: The sale price of an article including the sales tax is Rs. 616. The rate of sales tax is 10%. If the shopkeeper has made a profit of 14%, then the cost price of the article is:
A.500
B.540
C.555
D.664
Answer: B.540
Explanation: 110% of S.P. = 616
S.P. = (616 * 100)/110 = Rs. 560
C.P = (110 * 560)/114 = Rs. 540
Answer: Option B
Question: If x+y=2 and x2y3 + y2x3=32, what is the value of xy?
A.1
B.2
C.3
D.4
Answer: D.4
Explanation: xy=4
As x+y=2
x2y3+y2x3=32
x2y2(y+x)=32
Substituting x+y
x2y2=16
xy=4
ANSWER:D
Question: A work can be finished in 17 days by twenty eight women. The same work can be finished in seven days by seventeen men. The ratio between the capacity of a man and a woman is
A.4:3
B.1:4
C.2:3
D.3:2
Answer: B.1:4
Explanation: Work done by 28 women in 1 day = 1/17
Work done by 1 woman in 1 day = 1/(17Ã—28)
Work done by 17 men in 1 day = 1/17
Work done by 1 man in 7 day = 1/(17Ã—7)
Ratio of the capacity of a man and woman =1/(17Ã—7) : 1/(17Ã—28) = 1/7 : 1/28
= 1/1 :1/4 = 1:4
Answer is B.
Question: A and B can finish a work in 10 days while B and C can do it in 18 days. A started the work, worked for 5 days, then B worked for 10 days and the remaining work was finished by C in 15 days. In how many days could C alone have finished the whole work ?
A.30 days
B.15 days
C.45 days
D.24 days
Answer: C.45 days
Explanation: Let C completes the work in x days.
Work done by (A + B) in 1 day = 1⁄10
Work done by (B + C) in 1 day = 1⁄18
A’s 5 days’ work + B’s 10 days’ work + C’s 15 days’work = 1
or (A + B)’s 5 days’ work + (B + C)’s 5 days’ work + C’s 10 days’ work = 1
or 5⁄10 + 5⁄18 + 10⁄x = 1 or x = 45 days
Answer C
Question: Find compound interest on Rs. 5000 at 12% per annum for 1 year, compounded half-yearly.
A.Rs. 600
B.Rs. 618
C.Rs. 525
D.Rs. 620
Answer: B.Rs. 618
Explanation: Principal = Rs.5000, Rate=6% per half year Time = 1 year = 2 half-years Amount = Rs. {5000 x ( 1 + 6/100)2] = Rs. [ 5000 x 53/50 x 53/50 ] = Rs. 5618 C.I. = Rs. (5618 – 5000) = Rs. 618
Answer B
Question: What is 10-8+6-4+...+(-16)?
A. 8
B. 10
C. 12
D. 14
Answer: D. 14
Explanation: The expression considers all even numbers between 10 and -16 with alternate addition and subtraction of the numbers.
The numbers to be used are: 10, 8, 6, 4, 2, 0, -2, -4, -6, -8, -10, -12, -14, and -16.
Now, the first term is positive and the next term is subtracted. So, the required expression becomes,
10 - 8 + 6 - 4 + 2 - 0 + (-2) - (-4) + (-6) - (-8) + (-10) - (-12) + (-14) - (-16)
= 10 - 8 + 6 - 4 + 2 - 0 - 2 + 4 - 6 + 8 - 10 + 12 - 14 + 16
= 58 - 44
= 14
Hence the correct answer choice is D.
Question: Martha has the unique talent of being able to guess other people’s height and weight. For every six people that Martha meets, she consistently guesses the people’s correct height five times, and for every eight people that she meets, she consistently guesses the people’s correct weight six times. If Martha meets three people and her success rate remains constant, what is the probability that Martha correctly guesses a person’s weight and height at least once?
A.8/27
B.2/5
C.485/512
D.98/125
Answer: C.485/512
Explanation: Probability that she guesses the height correctly P(h)=5/6
Probability that she guesses the weight correctlyP(w)=6/8
Probability that she guesses both weight and height correctly(P(h)*P(w))=5/6 * 6/8= 30/48
Now the Q asks about the probability of this happening atleast once.
We calculate it by finding the probability of not being able to guess in any of the three occasions.
Probability of not being able to guess any no. of times =1-30/48=18/48=3/8
For all three occasions P(A)=3/8 * 3/8 * 3/8=27/512
Probability of the event happening atleast once=1- P(A)=1-27/512=485/512
Ans should be C
Question: A train 240 m in length crosses a telegraph post in 16 seconds. The speed of the train is?
A.50 kmph
B.62 kmph
C.54 kmph
D.74 kmph
Answer: B.62 kmph
Explanation: B
54 kmph
S = 240/16 * 18/5 = 54 kmph
Question: Two trains, one from Howrah to Patna and the other from Patna to Howrah, start simultaneously. After they meet, the trains reach their destinations after 9 hours and 16 hours respectively. The ratio of their speeds is?
A.4:5
B.4:3
C.4:4
D.4:8
Answer: B.4:3
Explanation: Let us name the trains A and B.
Then, (A's speed) : (B's speed)
= √b : √a = √16 : √9
= 4:3
Answer: B
Question: Each digit in the two-digit number G is halved to form a new two-digit number H. Which of the following numbers could be the sum of G and H?
A.153
B.150
C.137
D.135
Answer: D.135
Explanation: Let x be the original 2-digit number.
If each digit is halved, then the sum of G and H is 3x/2.
Note the sum must be a multiple of 3 and less than 150.
Only 135 satisfies these two conditions.
The answer is D.
Question: The third proportional to 1 and 2 is?
A.8
B.7
C.4
D.5
Answer: C.4
Explanation: (2*2)/1 = 4
Answer:C
Question: (A% of 6B + B% of A) is equal to ?
A.A% of B
B.B% of A
C.7% of AB
D.AB% of 3
Answer: C.7% of AB
Explanation: Answer
A% of 6B + B% of A =6AB/100 + AB/100
= 7AB/100 = 7% of AB
Correct Option: C
Question: If k is the sum of the digits of integer m, and m=10n, where n is an integer, which of the following must be true?
A.k is not divisible by 9
B.The sum of the digits of k is divisible by 3
C.m is a multiple of 10k
D.k is a multiple of 9
Answer: C.m is a multiple of 10k
Explanation: m= 10n i.e n =1,2,3 ,4 etc or -1,-2.-3 ,-4 then m =10,20,30,40 or -10 ,-20 ,-30 ,-40 then k 1,2, 3,4 or -(1+0) , -(2+0) , -(3+0) ,-(4+0) .
ans(C)
Question: A can do a job in 18 days and B can do it in 30 days. A and B working together will finish twice the amount of work in days?
A.29 ½ days
B.22 ½ days
C.92 ½ days
D.28 ½ days
Answer: B.22 ½ days
Explanation: 1/18 + 1/30 = 8/90 = 4/45
45/4 = 11 ¼ *2
=22 ½ days
Answer:B
Question: The average of 1st 3 of 4 numbers is 16 and of the last 3 are 15. If the sum of the first and the last number is 13. What is the last numbers?
A.6
B.7
C.5
D.4
Answer: C.5
Explanation: A + B + C = 48
B + C + D = 45
A + D = 13
A – D = 3
A + D = 13
2D = 10
D = 5
Answer:C
Question: The R students in a class agree to contribute equally to buy their teacher a birthday present that costs y dollars. If w of the students later fail to contribute their share, which of the following represents the additional number of dollars that each of the remaining students must contribute in order to pay for the present?
A. y/R
B. y/(R-x)
C. xy/(R-x)
D. wy/(R(R-w))
Answer: D. wy/(R(R-w))
Explanation: y/(R-w)- y/R
if we simplify this we get choice D, which is the correct answer.
Question: A and B together can do a piece of work in 30days. A having worked for 16days, B finishes the remaining work alone in 44days. In how many days shall B finish the whole work?
A.60
B.12
C.24
D.30
Answer: A.60
Explanation: Let A's 1day work = x
B's 1day work = y
x+y = 1/30
16x+44y = 1
x = 1/60
y = 1/60
B's 1 day work = 1/60
B alone can finish the job in 60 days
Answer is A
Question: In an examination, 5% of the applicants were found ineligible and 85% of the eligible candidates belonged to the general category. If 4275 eligible candidates belonged to other categories, then how many candidates applied for the examination?
A.28000
B.30000
C.32000
D.33000
Answer: B.30000
Explanation: Explanation :
Let the number of candidates applied for the examination = x
Given that 5% of the applicants were found ineligible.
It means that 95% of the applicants were eligible (∴ 100% - 5% = 95%)
Hence total eligible candidates = 95x/100
Given that 85% of the eligible candidates belonged to the general category
It means 15% of the eligible candidates belonged to other categories(∴ 100% - 85% = 15%)
Hence Total eligible candidates belonged to other categories
= total eligible candidates × (15/100) = (95x/100) × (15/100)
= (95x × 15)/(100 × 100)
Given that Total eligible candidates belonged to other categories = 4275
⇒ (95x × 15)/(100 × 100) = 4275
⇒ (19x × 15)/(100 × 100) = 855
⇒ (19x × 3)/(100 × 100) = 171
⇒ (x × 3)/(100 × 100) = 9
⇒ x/(100 × 100) = 3
⇒ x = 3 × 100 × 100 = 30000
Answer : Option B
Question: P and Q are both positive integers. When P is divided by Q, the remainder is some positive integer D, and when P is divided by (Q + 5), the remainder is also D. If P/Q = 1020.75 and P/(Q + 5) = 816.6, then which of the following gives the correct set of {D, Q}?
A.{6, 12}
B.{6, 15}
C.{15,20}
D.{9, 15}
Answer: C.{15,20}
Explanation: p/q= d=p/q+5
d= .75 q
d= .6(q+5)
we get d = 15 and q = 20. Answer = C.
Question: When a is divided by b, the quotient is c with remainder 6. What is a in terms of 6, b, and c?
A.bc+6
B.bc/6
C.bc-6
D.b/c
Answer: A.bc+6
Explanation: a/b =c with remainder 6
i.e, a-6 = bc
a= bc+6
Answer : A
Question: All of the positive integers are written in a triangular pattern, beginning with the following
four lines and continuing in the same way:
1
2 3 4
5 6 7 8 9
10 11 12 13 14 15 16
Which number appears directly below 2012?
A.2100
B.2102
C.2104
D.2106
Answer: B.2102
Explanation: Observe that the nth row has 2n- 1 numbers, that each number on the 2nth row is
equal to 2n-2 plus the one above it, and that the last number in the nth row is n2. (The latter
fact may be proved by observing that n2- (n- 1)2 = 2n- 1, the length of the nth row.)
442 = 1936 and 452 = 2025, so that 2012 is on the 45th row. The number below it will be
larger by (2 * 46- 2), so it will be 2102.
correct answer B
Question: The product of all the prime numbers less than 20 is closest to which of the following powers of 10 ?
A.10^9
B.10^8
C.10^7
D.10^6
Answer: C.10^7
Explanation: We should find the approximate value of 2*3*5*7*11*13*17*19 to some power of 10.
# of different approximations are possible.
Approach #1:
2*5=10;
3*7=~20 (actually more than 20);
11*19=~200 (actually more than 200);
13*17=~200 (actually more than 200);
2∗3∗5∗7∗11∗13∗17∗19≈10∗20∗200∗200=8∗106≈107
Answer: C.
Approach #2:
2*5=10
3*17=~50 (actually more than 50);
7*13=~100 (actually less than 100);
11*19=~200 (actually more than 200)
2∗3∗5∗7∗11∗13∗17∗19≈10∗50∗100∗200=107.
Answer: C.
Question: There are 6 identical pens and 9 identical books. In how many different ways can a person select at least one object from this set?
A.15
B.30
C.69
D.78
Answer: C.69
Explanation: We can select from 0 to 6 pens and from 0 to 9 books.
Thus the total possible ways to select objects is 7*10 = 70
We must subtract 1 for the case with 0 pens and 0 books.
The answer is C.
Question: Two pipes can fill the cistern in 10hr and 12 hr respectively, while the third empty it in 15hr. If all pipes are opened simultaneously, then the cistern will be filled in
A.7.5 hr
B.8 hr
C.8.57 hr
D.10 hr
Answer: C.8.57 hr
Explanation: Solution:
Work done by all the tanks working together in 1 hour.
1/10+1/12−1/15=7/60
Hence, tank will be filled in 60/7=8.57 hour
Option(C)
Question: The population of a town increased from 1,34,800 to 2,42,500 in a decade. The average percent increase of population per year is:
A.4.37%
B.7.9%
C.6.8%
D.8.75%
Answer: B.7.9%
Explanation: Explanation: Increase in 10 years = (242500 - 134800) = 107700
Increase% = (107700/134800 x 100)% = 79%.
Required average = (79/10)% = 7.9%.
Answer: Option B
Question: In a company of 160 employees, 90 are females. A total of 80 employees have advanced degrees and the rest have a college degree only. If 40 employees are males with college degree only, how many employees are females with advanced degrees?
A.40
B.45
C.50
D.55
Answer: C.50
Explanation: The number of males is 160-90=70.
The number of males with advanced degrees is 70-40=30.
The number of females with advanced degrees is 80-30=50.
The answer is C.
Question: A, B and C started a business with capitals of Rs. 8000, Rs. 10000 and Rs. 12000 respectively. At the end of the year, the profit share of B is Rs. 1400. The difference between the profit shares of A and C is?
A.288
B.560
C.155
D.600
Answer: B.560
Explanation: Ratio of investments of A, B and C is 8000 : 10000 : 12000 = 4 : 5 : 6
And also given that, profit share of B is Rs. 1400
=> 5 parts out of 15 parts is Rs. 1400
Now, required difference is 6 - 4 = 2 parts
Required difference = 2/5 (1400) = Rs. 560
Answer:B
Question: Two trains, one from Howrah to Patna and the other from Patna to Howrah, start simultaneously. After they meet, the trains reach their destinations after 49 hours and 25 hours respectively. The ratio of their speeds is?
A.4:9
B.5:7
C.4:5
D.4:1
Answer: B.5:7
Explanation: Let us name the trains A and B.
Then, (A's speed) : (B's speed)
= √b : √a = √25 : √49
= 5:7
Answer:B
Question: A father said to his son, "I was as old as you are at the present at the time of your birth". If the father's age is 42 years now, the son's age 5 years back was:
A.12 years.
B.14 years.
C.16 years.
D.17 years.
Answer: C.16 years.
Explanation: Let the son's present age be x years. Then, (42 - x) = x
2x = 42.
x = 21
Son's age 5 years back (21- 5) = 16 years.
ANSWER :C
Question: Simplify 3/4 of 6 0 – 8/5 of 60 + ? = 12
A.48
B.24
C.56
D.63
Answer: D.63
Explanation: 60 × 3/4 = 45, 60 × 8/5 = 96
45 – 96 + ? = 12 => 96 + 12 = 108 – 45 = 63
[63 + 45 = 108 – 96 = 12]
Option D
Question: Find out the C.I on Rs.5000 at 4% p.a. compound half-yearly for 1 1/2 years.
A.306.09
B.306.05
C.306.04
D.306.02
Answer: C.306.04
Explanation: A = 5000(51/50)3
= 5306.04
5000
-----------
306.04
Answer:C
Question: A person spends 1/5th of his income on the education of his children, and 20% of the remaining on food. If he is left with Rs.576 find his income?
A.800
B.900
C.700
D.750
Answer: B.900
Explanation: X * 4/5 * 80/100 = 576
X = 14400/16
X = 900
ANSWER B
Question: If two positive numbers are in the ratio 1/12 : 1/9, then by what percent is the second number more than the first?
A.70%
B.90%
C.33.33%
D.50%
Answer: C.33.33%
Explanation: Given ratio = 1/12 : 1/9 = 9 : 12
Let first number be 9x and the second number be 12x.
The second number is more than first number by 3x.
Required percentage = 3x/9x * 100 = 33.33%.
Answer:C
Question: S = { 1,2,3,5,6,9}
T = { 4,5,6,7,1,3}
what is the probability that x chosen from S and y chosen from T will result x*y = even
A.5/9
B.3/2
C.1/2
D.5/6
Answer: A.5/9
Explanation: p: the probability that x*y is even, then p=1-p(x*y is odd)
p(x*y odd)=p(x odd)*p(y odd)=4/6*4/6=16/36=4/9
And p=1-4/9=5/9
Option: A
Question: Out of 15 consecutive numbers, 2 are chosen at random. The probability that they are both odds or both primes is?
A.1/6
B.1/7
C.1/4
D.1/1
Answer: B.1/7
Explanation: A leap year has 52 weeks and two days
Total number of cases = 7
Number of favourable cases = 1
i.e., {Saturday, Sunday}
Required Probability = 1/7.Answer:B
Question: Reena took a loan of Rs. 1200 with simple interest for as many years as the rate of interest. If she paid Rs. 300 as interest at the end of the loan period, what was the rate of interest?
A.3.6
B.5
C.18
D.Cannot be determined
Answer: B.5
Explanation: let rate = R% and time = R years
Then ( 1200 x R x R /100) = 300
=> 12R2= 300
=> R2= 25
=> R= 5
Answer B
Question: One pipe can fill a pool four times faster than a second pipe. When both pipes are opened, they fill the pool in eight hours. How long would it take to fill the pool if only the faster pipe is used?
A.5 hr
B.8 hr
C.10 hr
D.16 hr
Answer: C.10 hr
Explanation: fast pipe + slow pipe = together
One pipe fills the pool four times faster than the other pipe so,
hourly fill rates:
1/x + 1/4x = 1/8
Let x = number of hours it would take the fast pipe to fill the pool thus,
x=10 hours
Answer: C
Question: Which of the following is the Highest Common Factor of 20, 40 and 60?
A.8
B.10
C.6
D.20
Answer: D.20
Explanation: HCF IS2*2*5=20Ans is :D
Question: A standard Veggiematik machine can chop 36 carrots in 4 minutes. How many carrots can 6 standard Veggiematik machines chop in 4 minutes?
A.36
B.54
C.216
D.216
Answer: C.216
Explanation: ONE Veggiematik machine can chop 36 carrots in 4 minutes
So, ONE Veggiematik machine can chop (1.5)(36) carrots in (1.5)(4) minutes
In other words, ONE Veggiematik machine can chop 54 carrots in4minutes
So,SIXVeggiematik machines can chop (4)(54) carrots in4minutes
In other words, SIX Veggiematik machines can chop 216 carrots in4minutes
Answer C
Question: Consider a Number 3.1n4
n represent the hundredths digit in the number shown above. If the number is rounded to the nearest hundredth, which of the following could be the tenths digit in the rounded number?
A.3
B.2
C.1
D.4
Answer: C.1
Explanation: In this ques we are given the thousandth digit as 4, so the hundreth digit can take any value from 0-9. For the hundreth digit i considered 2 set of values (i) 0, 1, 2, 3 and (ii) 4, 5, 6, 7, 8, 9. Given that the thousandth digit is 4, the hundreth digit has to go up by 0, and correspondingly, the tenth digit should remain same.i.e 0-9.say 1
C
Question: Jack has two dice, one has six equally probable sides, labeled 1, 2, 3, 4, 5, 6, and the other has seven equally probable sides, labeled 1, 2, 3, 4, 5, 6, 7. If Jack rolls both dice what is the probability that both of the number's sum will be 13?
A.3/14
B.2/7
C.1/3
D.1/42
Answer: D.1/42
Explanation: Both Dice addition result is 13 = (6+7)
Probability that the number on first die is 6 = 1/6
Probability that the number on Second die is 7 = 1/7
Probability that Both Dice addition result is 13 = 1/6 * 1/7 = 1/42
D
Question: The ratio, by weight, of coffee to sugar to water in a pot of coffee is 7:3:15. The ratio is then altered so that the ratio of coffee to sugar is halved while the ratio of coffee to water is doubled. If the altered pot of coffee contains 12 grams of sugar, how many grams of water does it contain after alteration?
A.12
B.13
C.14
D.15
Answer: D.15
Explanation: The new ratio of coffee to sugar is 3.5:3
The new ratio of coffee to water is 14:15.
The new ratio of coffee to sugar to water is 14:12:15.
If there are 12 grams of sugar, then there are (15/12)*12=15 grams of water.
The answer is D.
Question: The probability that a man will be alive for 10more yrs is 1/4 & the probability that his wife will alive for 10 more yrs is 1/3. The probability that none of them will be alive for 10 more yrs, is
A.1
B.1/2
C.2/3
D.3/5
Answer: B.1/2
Explanation: Sol. Required probability = Pg.) x P(B) = (1— D x(1 —I) =: x 1=1/2
Ans.(B)
Question: If the area of a circle is 36pi square feet, find its circumference.
A.12 pi feet
B.28 pi feet
C.38 pi feet
D.48 pi feet
Answer: A.12 pi feet
Explanation: The area is given by pi *r* r. Hence
pi * r *r = 36 pi
r * r = 36; hence r = 36 feet
The circumference is given by
2 * pi * r = 2 * pi * 6 = 12 pi feet
correct answer A
Question: There are 5 white balls and 4 black balls in a bag. Second bag contains 7 white balls and 9 black balls. one ball is transferred from first bag to second. a single ball is taken out from second bag. What is the probability that the ball is white.
A.2/9
B.3/9
C.4/9
D.5/9
Answer: C.4/9
Explanation: lets divide this into 2 cases
case 1:When a black ball is transferred from bag 1 to 2
(4/9)*(7/17)=28/153
case 2: When a white ball is transferred from bag 1 to 2
(5/9)*(8/17)=40/153
total probability=(28/153)+(40/153)=4/9
ANSWER:C
Question: When magnified 1,000 times by an electron microscope, the image of a certain circular piece of tissue has a diameter of 5 centimeter. The actual diameter of the tissue, in centimeters, is
A. 0.005
B. 0.002
C. 0.001
D. 0.0005
Answer: A. 0.005
Explanation: It is very easy if x is the diameter, then the magnified length is 1000x.
ince 1000x=5 then x=5/1000=0.005.
The answer is A
Question: Two wheels are connected via a conveyor belt. The larger wheel has a 40cm diameter and the smaller wheel has a 32cm diameter. In order for the conveyor belt to work smoothly, each wheel must rotate the exact same number of centimetres per minute. If the larger wheel makes r revolution per minute, how many revolutions does the smaller wheel make per minute in terms of r?
A.1280π
B.1.25r
C.48r
D.24r
Answer: B.1.25r
Explanation: Interesting to note that the larger wheel has a diameter of 40 (8*5) while the smaller one has a diameter of 32 (8*4)...
If the large wheel has a diameter of 40 and the small wheel, 32, then their circumferences are 40pi and 32pi respectively. In order for them to move the conveyor belt at the same rate, the smaller wheel would need to rotate 1.25 times as fast as the larger wheel. Lets say the large wheel makes 10 revolutions per minute, the smaller wheel would need to make 10*1.25 = 12.5 revolutions per minute. If the large wheel makes 10 revolutions per minute . Therefore, the smaller wheel would need to make 10*1.25 = 12.5 revolutions per minute.
If r = 10, then the answer choice must be b.
B. 1.25r
Question: The area of a triangle will be when a = 1m, b = 2m, c = 3m, a, b, c being lengths of respective sides?
A.0 sq m
B.7 sq m
C.5 sq m
D.4 sq m
Answer: A.0 sq m
Explanation: S = (1 + 2 + 3)/2 = 3
=> No triangle exists
Answer:A
Question: A train 110 m long is running with a speed of 60 km/hr. In what time will it pass a man who is running at 6 km/hr in the direction opposite to that in which the train is going?
A.8
B.6
C.5
D.54
Answer: B.6
Explanation: Speed of train relative to man = 60 + 6 = 66 km/hr.
= 66 * 5/18 = 55/3 m/sec.
Time taken to pass the men = 110 * 3/55 = 6 sec.
Answer: B
Question: A pupil's marks were wrongly entered as 83 instead of 63. Due to the average marks for the class got increased by half. The number of pupils in the class is?
A.18
B.82
C.40
D.27
Answer: C.40
Explanation: Let there be x pupils in the class.
Total increase in marks
= (x * 1/2) = x/2
x/2 = (83 - 63) => x/2
= 20 => x = 40.
Answer: C
Question: If the sum and difference of two numbers are 20 and 10 respectively, then the difference of their square is:
A.12
B.28
C.160
D.200
Answer: D.200
Explanation: Let the numbers be x and y.
Then, x + y = 20 and x - y = 8
x2 - y2 = (x + y)(x - y) = 20 * 10 = 200.
ANSWER:D
Question: If p<0, which of the following must be true?
A.–100 < p < 100
B.p ≤ –1
C.p ≤ 1
D.p^2 ≥ 1/4
Answer: C.p ≤ 1
Explanation: p is a negative number.
A. –100 < p < 100p can be a negative number less than -100
B. p ≤ –1p can be a fraction, in which case it would be greater than -1
C. p ≤ 1must be true since 1 is positive and p is negative
D. p^2 ≥ 1/4not true if p is a negative fraction like -1/5
E. –100 < p < 0p can be a negative number less than -100=C
Question: What is the minimum number of square marbles required to tile a floor of length 2 metres 89 cm and width 3 metres 74 cm?
A.176
B.187
C.374
D.748
Answer: C.374
Explanation: The marbles used to tile the floor are square marbles.
Therefore, the length of the marble=width of the marble.the length of the marble=width of the marble.
As we have to use whole number of marbles, the side of the square should a factor of both 2 m 89 cm and 3m 74. And it should be the highest factor of 2 m 89 cm and 3m 74.
2m 89 cm = 578 cm and 3 m 74 cm = 374 cm.
The HCF of 289 and 374 = 34.
Hence, the side of the square is 17.
The number of such square marbles required,
=289×374/17×17
=374 marbles
Option(C)
Question: If x and y are different integers and x^2 = xy, which of the following must be true ?
I. x = 1
II. y = 0
III. x = 0
A.I only
B.II only
C.III only
D.I and III only
Answer: C.III only
Explanation: Answer choice A is correct.
The question gives you x^2=xy
you can simplify that as x^2-xy=0
x(x-y)=0 the solution will be either x=0 or x=y, since x and y are different integers x cannot equal y, that leaves you x=0 to be the only answer.
Answer C
Question: The sum of the numbers is 110. If the first number be twice the second and third number be one-third of the first, then the second number is:
A.30
B.54
C.72
D.84
Answer: A.30
Explanation: Let the second number be x. Then, first number = 2x and third number = 2x/3.
2x + x + 2x/3 = 110
11x/3 = 110
x = 30
ANSWER:A