RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: 8 men, working 8 hours a day can complete a work in 24 days. How many hours a day must 12 men work to complete the same work in 16 days?
A.6
B.7
C.8
D.9
Answer: C.8
Explanation: The number of hours required to complete the work is 8*8*24 = 1536
12 × 16 × (x) = 1536
x = 8
The answer is C.
Question: I. j; k; m; n; p
II. j - 10; m; m; m; p + 15
III. j + 2; k + 1; m; n - 1; p - 2
If j, k, m, n, and p are consecutive positive integers such that j < k < m < n < p, the data sets I, II, and III above are ordered from greatest standard deviation Z to least standard deviation in which of the following?
A. I, III, II
B. II, I, III
C. II, III, I
D. III, I, II
Answer: B. II, I, III
Explanation: Range of 1st Set = (p-j)
Range of 2nd Set = P+15 - j +10 = (p-j) +25
Range of 3rd Set = P -2 - j - 2 = (p-j) - 4
R2 > R1 > R3 ==> SD2 > SD1 > SD3
Since, Z=Higher the Range -> More Dispersion in the Set -> More Standard Deviation.B
Question: Find the remainder of 1421 x 1423 x 1425 when divided by 12
A.0
B.1
C.2
D.3
Answer: D.3
Explanation: 1421 x 1423 x 1425 / 12
= (12*118+5)*(12*118+7)*(12*118+9)/ 12
=> rem[(5*7*9)/12]
=> rem[(35*9)/12]
=> rem[(36-1)*9/12]
=> rem[(-9)/12]
=> rem = 3
ANSWER:D
Question: 1000 men have provisions for 15 days. If 300 more men join them, for how many days will the provisions last now?
A.11.5
B.12.5
C.12.6
D.12.2
Answer: A.11.5
Explanation: 1000*15 = 1300*x
x = 11.5
Answer: A
Question: 9548 + 7314 = 3362 + (?)
A.8300
B.8400
C.13500
D.8700
Answer: C.13500
Explanation: 9548 16862 = 3362 + x
+ 7314 x = 16862 - 3362
----- = 13500
16862
-----
C)
Question: The distance between A&B is 450km. A person is traveling from A to B at 70km/hr started at 9AM and another person is traveling from B to A at 80km/hr and started at same time. Then at what time they meet together.?
A.A)12PM
B.B)4PM
C.C)1PM
D.D)3PM
Answer: A.A)12PM
Explanation: Let x hours be they will meet together
distance covered by 1st person+distance covered by 2nd person = 450km
70x+80x = 450
x= 3 hr
They will meet = 9AM +3hr = 12PM
Answer is A
Question: In how many ways can you seat 8 people on a bench if one of them, Rohit, does not want to sit on the middle seat or at either end?
A.720
B.1720
C.25200
D.5040
Answer: C.25200
Explanation: Since Rohit does not want to sit on the middle seat or at either end (3 chairs), then he can choose 5 chairs to sit. The remaining 7 people can sit in 7! ways. Thus the # of arrangements is 5*7! = 25,200.
Answer: C.
Question: If 3x−y=27 and 3x+y=243, then find the value of x
A.1
B.2
C.3
D.4
Answer: D.4
Explanation: Explanation:
3x−y=27=33<=>x−y=3... (i)3x+y=243=35<=>x+y=5... (ii) adding (i) and (ii)=>2x=8=>x=4
Option D
Question: John, Mac and Tonny together can do a work in 20 days. John alone can do the work in 80 days and Mac alone can do the same work in 70 days. Find in what time Tonny alone can do that work?
A.50days
B.43.08days
C.53.80days
D.35days
Answer: B.43.08days
Explanation: The required answer is = 20*80*70 / 80*70-20(80+70)
= 112000/2600 = 43.08days
Answer is B
Question: A train running at the speed of 60 km/hr crosses a pole in 9 seconds. What is the length of the train?
A.120 meters
B.180 meters
C.324 meters
D.150 meters
Answer: D.150 meters
Explanation: Speed=(60 x(5/18)m/sec	=(50/3)m/sec.
Length of the train = (Speed x Time).
Length of the train =	((50/3)x 9)m = 150 m
D
Question: For any integer k greater than 1, the symbol k* denotes the product of all the fractions of the form 1/t, where t is an integer between 1 and k, inclusive. What is the value of 3*/4* ?
A.5
B.5/4
C.4/5
D.1/4
Answer: B.5/4
Explanation: When dealing with 'Symbolism' questions, it often helps to 'play with' the Symbol for a few moments before you attempt to answer the question that's asked. By understanding how the Symbol 'works', you should be able to do the latter calculations faster.
Here, we're told that K* is the PRODUCT of all the fractions of the form 1/T, where T is an integer between 1 and K, inclusive.
Based on this definition....
IF....
K = 2
K* = (1/1)(1/2) = 1/2
IF....
K = 3
K* = (1/1)(1/2)(1/3) = 1/6
We're asked to find the value of 5*/4*
Now that we know how the Symbol 'works', solving this problem shouldn't be too difficult. You can actually choose to do the math in a couple of different ways....
5* = (1/1)(1/2)(1/3)(1/4)(1/5)
Don't calculate this just yet though....since we're dividing by 4*, many of those fractions will 'cancel out.'
4* = (1/1)(1/2)(1/3)(1/4)
We're looking for the value of:
(1/1)(1/2)(1/3)(1/4)(1/5) / (1/1)(1/2)(1/3)(1/4)
Since the first four fraction in the numerator and denominator cancel out, we're left with just one fraction:
5/4
B
Question: The ratio of the volumes of two cubes is 27 : 125. What is the ratio of their total surface areas?
A.9 : 25
B.9 : 35
C.81 : 124
D.81 : 126
Answer: A.9 : 25
Explanation: Ratio of the sides = 3√27: 3√125 = 3 : 5
Ratio of surface areas = 3^2 : 5^2 = 9:25
Answer: Option A
Question: a+2b=6,ab=4
2/a + 1/b=?
A.3/2
B.5/2
C.7/2
D.9/2
Answer: A.3/2
Explanation: 2/2+1/2=1+1/2=3/2
ANSWER:A
Question: In a competitive examination in State ASS, 3% candidates got selected from the total appeared candidates. State BI had an equal number of candidates appeared and 5% candidates got selected with 12 more candidates got selected than ASS. What was the number of candidates appeared from each State?
A.500
B.250
C.300
D.1200
Answer: D.1200
Explanation: State ASS and State BI had an equal number of candidates appeared.
In state ASS, 3% candidates got selected from the total appeared candidates
In state BI, 5% candidates got selected from the total appeared candidates
But in State BI, 12 more candidates got selected than State ASS
From these, it is clear that 1% of the total appeared candidates in State BI = 12
=> total appeared candidates in State BI = 12 x 100 = 1200
=> total appeared candidates in State ASS = total appeared candidates in State BI = 1200
Answer : D
Question: There are 250 female managers in a certain company. Find the total number of female employees in the company, if 2/5 of all the employees are managers and 2/5 of all male employees are managers.
A.325
B.425
C.625
D.700
Answer: C.625
Explanation: as per question stem 2/5M (Portion of Men employees who are managers) + 250 (Portion of Female employees who are managers) = 2/5T (Portion of Total number of employees who are managers), thus we get that 2/5M+250 = 2/5T, or 2/5(T-M)=250, from here we get that T-M=625, that would be total number of female employees and the answer (C)
Question: Let the function W(n) represent the product of the first n prime numbers, where n > 0. If x = W(n) + 1, which of the following must be true?
(i) x is always odd
(ii) x is always prime
(iii) x is never the square of an integer
A.ii only
B.iii only
C.i and ii only
D.i and iii only
Answer: D.i and iii only
Explanation: W(n) is always even, because the first prime is 2 and no matter what n is, 2 always will be a divisor of W(n). Thus, W(n) + 1 = even + 1 = odd. So, (i) is always true.
Now, use logic:
If (ii) is true (so if x is always prime), then (iii) must automatically be true: no prime is the square of an integer. So, the correct answer must be i only; i, ii, and iii only; or i and iii only. since onlyi and iii onlyis among the options, then it must be true.
Or, since (i) is always true, then from options the answer must be either C or D. C cannot be correct because if (ii) is true, then so must be (iii). Thus only D remains.
Answer: D.
Question: What should come in place of the question mark (?) in each of the following questions ?
12 + 22 + 32 + ... + 102 = ?
A.400
B.625
C.380
D.385
Answer: D.385
Explanation: Explanation :
Sum of the squares of first 'n' natural number = n(n+l)(2n+l)/6 Put n = 10. 10x 11x21/6=55x7=385.
Answer : Option D
Question: The product of all the prime numbers less than 50 is closest to which of the following powers of 10 ?
A. 10^9
B. 10^8
C. 10^7
D. 25*10^6
Answer: D. 25*10^6
Explanation: 2*3*5*7*11*13*17*19
2*19*3*17*5*13*7*11
38*51*65*77
By approximation
40*50*70*70
2000*4900
By approximation
5000*5000
25,000,000
D
Question: 108.	Triangle A’s base is 20% greater than the base of triangle B, and A’s height is 20% less than the height of triangle B. The area of triangle A is what percent less or more than the area of triangle B?
A. 0.25 % less
B. 1 % less
C. Equal to each other
D. 1 % more
Answer: A. 0.25 % less
Explanation: Wish the question specified that we are talking about corresponding height.
Base of A = 21/20 * Base of B
Height of A = 19/20 * Height of B
Area of A = (1/2) * Base of A * Height of A = 21/20 * 19/20 * Area of B = 399/400 * Area of B
Area of A is 0.25% less than the area of B.
Answer (A)
Question: An employee’s annual salary was increased $15,000. If her new annual salary now equals $90,000, what was the percent increase?
A.15%
B.16 2⁄3%
C.20%
D.22%
Answer: C.20%
Explanation: New annual salary = $90,000
Salary increase = $15,000.
Original salary = $90,000 - $15,000.
= $75,000
%Increase = ($15,000/ $75,000 )*100
=20%
Hence C.
Question: A train is 360 meter long is running at a speed of 45 km/hour. In what time will it pass a bridge of 140 meter length?
A.87 seconds
B.67 seconds
C.40 seconds
D.67 seconds
Answer: C.40 seconds
Explanation: Speed = 45 Km/hr = 45*(5/18) m/sec = 25/2 m/sec
Total distance = 360+140 = 500 meter
Time = Distance/speed
= 500 * (2/25) = 40 seconds
Answer: C
Question: If Yury has been writing programming code for 13 hours at a rate of 5 lines of code per 20 seconds, how many lines of code has he written?
A.117(10^2)
B.126(10^3)
C.12.6(10^5)
D.1.26(10^7)
Answer: A.117(10^2)
Explanation: 5 LINES IN 20 SECONDS
SO FOR 1 MINUTE ( 5 X 3 = 15 LINES )
I HOUR = 60 MINUTES
15 X 60 = 900 LINES IN AN HOUR
13 HOURS = 900 X 13 = 117(10^2)
ANSWER A
Question: Without stoppages a train travels a certain distance with an average speed of 60 kmph and with stoppages it covers the same distance with an average speed of 20 kmph. What is the time in minutes per hour for which train stops?
A.30 min/hr
B.35 min/hr
C.40 min/hr
D.45 min/hr
Answer: C.40 min/hr
Explanation: Pick a smart number for the distance. lets say LCM 60
Without = 60/60 = 1 hours
With = 60/20= 3 hours
So in a trip of 3 hours, 2 hour is spent in stoppages
Hence, 120/3 = 40 min/hr on stoppages
Answer : C
Question: The average age of father and his two sons is 18 Years. Five years ago, the average age of the two sons was 11 Years. If the difference between the ages of the two sons is four years, what is the present age of the father?
A.22
B.24
C.25
D.28
Answer: A.22
Explanation: The total present age of father and two sons is 3x18 = 54 yrs
The total present age of sons is (11+5) X 2 = 32Years
so, present age of father is 54 â€“ 32 = 22 yrs
Answer A
Question: A sum was put at simple interest at a certain rate for 3 years. Had it been put at 2% higher rate, it would have fetched Rs. 360 more. Find the sum.
A.3000
B.6000
C.2000
D.4000
Answer: B.6000
Explanation: Let sum = P and original rate = R.
Then, [ (P*(R+2)*3)/100] – [ (P*R*3)/100] = 360.
= 3PR + 6P - 3PR = 36000  6P=36000  P=6000
Hence, sum = Rs. 6000.
Answer is B.
Question: The value of a machine depreciates at 20% per annum. If its present value is Rs. 1,50,000, at what price should it be sold after two years such that a profit of Rs. 26,000 is made?
A.Rs. 1,10,000
B.Rs. 1,20,000
C.Rs. 1,22,000
D.Rs. 1,21,000
Answer: C.Rs. 1,22,000
Explanation: The value of the machine after two years = 0.8 * 0.8 * 1,50,000 = Rs. 96,000
SP such that a profit of Rs. 24,000 is made = 96,000 + 26,000 = Rs. 1,22,000
ANSWER:C
Question: A man is 16 years older than his son. In two years, his age will be twice the age of his son. The present age of this son is
A.21 years
B.14 years
C.16 years
D.18 years
Answer: B.14 years
Explanation: Explanation:
Let's Son age is x, then Father age is x+16.
=> 2(x+2) = (x+16+2)
=> 2x+4 = x+18
=> x = 14 years
Option B
Question: If p/q =4/5, then the value of 4/7 + {(2q - p) / (2q + p)} is ?
A.3 / 7
B.34
C.1
D.2
Answer: C.1
Explanation: Answer
Given Exp. = 4 / 7 + {(2q - p) / (2q + p)}
Dividing numerator as well as denominator by q,
Exp = 4/7 + {2-p/q) / (2 + p/q)}
= 4/7 + {(2 - 4/5) / (2 + 4/5)}
= 4/7 + 6/14
= 4/7 + 3/7
=7/7
=1.
Correct Option: C
Question: A person was going through train from Bombay to Pune. After every five minutes he finds a train coming from opposite direction. Velocity of trains are equal of either direction. If the person reached Pune in one hour then how many trains he saw in the journey ?
A.9
B.10
C.11
D.12
Answer: C.11
Explanation: 11
ANSWER:C
Question: Rahim bought 65 books for Rs.1150 from one shop and 50 books for Rs.920 from another. What is the average price he paid per book ?
A.28
B.18
C.27
D.29
Answer: B.18
Explanation: Average price per book
= (1150 + 920) / (65 + 50)
= 2070 / 115
= Rs.18
Answer:B
Question: How much water must be added to 56 litres of milk at 1 1⁄2 litres for 20 so as to have a mixture worth 10 2⁄3 a litre?
A.10 litres
B.12 litres
C.14 litres
D.18 litres
Answer: C.14 litres
Explanation: C.P. of 1 litre of milk = (20 × 2⁄3) = 40⁄3
∴ Ratio of water and milk = 8⁄3 : 32⁄3 = 8 : 32 = 1 : 4
∴ Quantity of water to be added to 56 litres of milk
= (1⁄4 × 56) litres = 14 litres.
Answer C
Question: Resident of town X participated in a survey to determine the number of hours per week each resident spent watching television. The distribution of the results of the survey had a mean of 21 hours and std deviation of 5 hrs. The number of hours that pat, a resident of town X, watched television last week was between 1 and 2 standard deviation below the mean. Which of the following could be the number of hours that Pat watched television last week?
A.30
B.20
C.18
D.12
Answer: D.12
Explanation: 21-12 < no of hrs < 21-5
9< no of hrs < 16.
D
Question: Increasing the original price of an article by 5 percent and then increasing the new price by 5 percent is equivalent to increasing the original price by
A.10.25%
B.12.5%
C.14.75%
D.15.15%
Answer: A.10.25%
Explanation: 1.05*1.05*x = 1.1025*x
The answer is A.
Question: S1 = 7 S2 = 10 ... Sn = 3n + 4 For the sequence above, in which any term n is defined as 3n + 4, what is the value of n for the first term in the sequence to exceed 50?
A.13
B.12
C.16
D.14
Answer: C.16
Explanation: term 16 = 3*16+4 = 52
Answer : C
Question: In a particular library there are 5 computer clusters open for public use. Each Computer Clusters has 40 Tablets. In the 1st week, 75 tablets are used, while 155 tablets are used in the second week, 30 in the third week & 140 in 4th week. Approximately what fraction of the library's computer facilities are in use per month?
A.1/3
B.1/4
C.1/2
D.2/3
Answer: C.1/2
Explanation: Total number of tablets = 40*5 = 200
Fraction of library's computer facilities used,
1st week = 75/200 = 3/8
2nd week = 155/200 = 31/40
3rd week = 30/200 = 3/20
4th week = 140/200 = 7/10
Fraction of library's computer facilities used per month
= (3/8+31/40+3/20+7/10)/4
=1/2
ANSWER:C
Question: If 4a = 16b and 6b = 13c, Find a:b:c?
A.52:13:6
B.13:7:52
C.7:13:52
D.7:13:54
Answer: A.52:13:6
Explanation: Explanation:
(4a = 16b ==> a/b = 16/4)
and (6b = 13c ==> b/c = 13/6)
==> a:b = 16:4 and b:c = 13:6
a:b:c = 52:13:6
Answer: Option A
Question: A certain sum of money doubles itself in 10 years in how much many years will it trible itself at the same rate?
A.20 years
B.66 years
C.77 years
D.44 years
Answer: A.20 years
Explanation: 100 ---- 100 --- 10
100 --- 10
--------------------
300 ---- 20 years .Answer: A
Question: Palindromes are words or phrases that read the same in both directions, e.g. EYE Now consider the word LEVEL, such a word is known as palindromes. Find the maximum possible number of five letter palindromes.
A.17515
B.17566
C.17576
D.17655
Answer: C.17576
Explanation: The first letter from the right can be chosen in 26 ways because there are 26 alphabets. Having chosen this, the second letter can be chosen in 26 ways. => The first two letters can be chosen in 26*26=676 ways Having chosen the first two letters, the third letter can be chosen in 26 ways. => All the three letters can be chosen in 676*26=17576 ways. It implies that the maximum possible number of five letter palindromes is 17576 because the fourth letter is the same as the second letter and the fifth letter is the same as the first letter.
Answer C
Question: The sum of 77 consecutive integers is 7777. What is the greatest integer in the set?
A.139
B.141
C.143
D.145
Answer: A.139
Explanation: Let x be the first integer in the set. Then x+76 is the largest integer.
The sum is: x+(x+1)+(x+2)+...+(x+76)
= 77x + 76*77/2
= 77(x+38)
Then x+38=101
x=63
The largest integer in the set is 63+76=139
The answer is A.
Question: The average age of husband, wife and their child 3 years ago was 27 years and that of wife and the child 5 years ago was 25 years. The present age of the husband is
A.40
B.30
C.45
D.55
Answer: B.30
Explanation: Explanation:
Sum of the present ages of husband, wife and child = (27 * 3 + 3 * 3) years = 90 years.
Sum of the present ages of wife and child = (25 * 2 + 5 * 2) years = 60 years.
Husband's present age = (90 - 60) years =30 years
Option B
Question: The area of a square is equal to five times the area of a rectangle of dimensions 125 cm * 64 cm. What is the perimeter of the square?
A.297 cm
B.178 cm
C.800 cm
D.287 cm
Answer: C.800 cm
Explanation: Area of the square = s * s = 5(125 * 64)
=> s = 25 * 8 = 200 cm
Perimeter of the square = 4 * 200
= 800 cm.
Answer:C
Question: A boy wants to go abroad by boat and return by flight. He has a choice of 9 different boat to go and 5 flight to return. In how many ways, can the boy perform his journey?
A.20
B.25
C.30
D.45
Answer: D.45
Explanation: Ans.(D)
Sol. Number of choices to go by ship = 9 Number of choices to return by airline = 5 From, fundamental principle, total number of ways of performing the journey = 9 x 5 = 45 ways
Question: By mixing two brands of tea and selling the mixture at the rate of Rs. 177 per kg. a shopkeeper makes a profit of 18%. If to every 2 kg of one brand costing Rs. 200 per kg, 3 kg of the other brand is added, then how much per kg does the other brand cost?
A.116.68
B.116.11
C.116.19
D.116.66
Answer: D.116.66
Explanation: Explanation:
Let the cost of the brand be Rs. X per kg.
C.P. of 5 kg = (2 * 200 + 3 * x) = Rs. (400 + 3x)
S.P of 5 kg = Rs. (5 * 177) = Rs. 885
[885 - (400 + 3x)]/(400 + 3x) * 100 = 18
24250 - 150x = 3600 + 27x
177x = 20650 => x = 116 2/3
So, cost of the other brand = Rs. 116.66.
Answer: D
Question: In a game of 100 points, A can give B 20 points and C 25 points. then how many points can B give C in a game of 70?
A.4.38
B.6.38
C.7.38
D.8.38
Answer: A.4.38
Explanation: In a game of 100 points,A give B 20 points and c 25 points means B=80,C=75
In 80 points B give 5 since 80-75=5
In 70 points B gives=70*5/80=4.38
ANSWER:A
Question: Y is the set of all positive integers x such that x^2 is a multiple of both 27 and 375. Which of the following integers must be a divisor of every integer x in Y?
I. 9
II. 15
III. 27
A.I only
B.II only
C.I and II only
D.I and III only
Answer: C.I and II only
Explanation: Ans: C
Y->{x} where x^2 is a multiple of both 27 and 375 means 3^3 and (5^3)*3
means x must contain 3^2 and 5^2
so with these conditions we know that 9=3^2 and 15=3*5 both have required factors for the divisibility of lowest int for x which is 9*25
but 27 is not a divisor because it can't divide 9*25 fully.
so Ans : C
Question: How many five digit numbers can be formed by using the digits 0,1,2,3,4,5 such that the number is divisible by 4?
A.134
B.144
C.154
D.164
Answer: B.144
Explanation: divisible by 4 means last two digit should always div by 4.
unit place=(04,20,40,12,24,32,52)
_ _ _04
_ _ _ 20
_ _ _40
total no=4x3x2x3=72
_ _ _12
_ _ _24
_ _ _32
_ _ _52
total no=3x3x2x4=72
total n0 = 72+72=144
ANSWER:B
Question: Excluding stoppages, the speed of a train is 45 kmph and including stoppages it is 36 kmph. Of how many minutes does the train stop per hour?
A.10 min
B.15 min
C.24 min
D.12 min
Answer: D.12 min
Explanation: Explanation:
T = 9/45 * 60 = 12 min
D)
Question: If m, n, and o are positive numbers such that (m/(m+n))(10) + (n/(m+n))(20)=o and if m<n which of the following could be the value of o?
A.10
B.12
C.15
D.18
Answer: D.18
Explanation: The answer is D. For any positive m and n, o is a number between 10 and 20. Since m < n, weight of 10 is inferior of weight of 20 -> o is > 15 -> 18 is the answer.
Question: If a tire rotates at 400 revolutions per minute when the car is traveling 48km/h, what is the circumference of the tire?
A.2 meters
B.6 meters
C.5 meters
D.3 meters
Answer: A.2 meters
Explanation: 400 rev / minute = 400 * 60 rev / 60 minutes
= 24,000 rev / hour
24,000 * C = 48,000 m : C is the circumference
C = 2 meters
correct answer A
Question: A train 400 m long can cross an electric pole in 20 sec and then find the speed of the train?
A.18 Kmph
B.17 Kmph
C.72 Kmph
D.18 Kmph
Answer: C.72 Kmph
Explanation: Length = Speed * time
Speed = L/T
S = 400/20
S = 20 M/Sec
Speed= 20*18/5 (To convert M/Sec in to Kmph multiply by 18/5)
Speed = 72 Kmph
Answer: C
Question: A circular dartboard of radius 1 foot is at a distance of 20 feet from you. You throw a dart at it and it hits the dartboard at some point Q in the circle. What is the probability that Q is closer to the center of the circle than the periphery?
A.0.75
B.1
C.0.25
D.0.5
Answer: C.0.25
Explanation: radius of inner dartboard/overall radius of dartboard
((r/2)^2)/(r^2)=1/4=0.25
ANSWER:C
Question: If a man walks at a rate of 5kmph, he misses a train by 7minutes. However, if he walks at the rate of 6kmph, he reaches the station 5minutes before the arrival of the train. Find the distance covered by him to reach the station.
A.8
B.4
C.15
D.6
Answer: D.6
Explanation: Let the required distance x km
difference in the times taken at two speeds = 12min = 1/5 hr
(x/5)-(x/6) = 1/5
x = 6
the required distance is 6 km
Answer is D
Question: Today is Varun's birthday. One year, from today he will be twice as old as he was 12 years ago. How old is Varun today ?
A.33
B.98
C.25
D.29
Answer: C.25
Explanation: Explanation:
Let Varun's age today = x years.
Then, Varun's age after 1 year = (x + 1) years.
Therefore x + 1 = 2 (x - 12) x + 1 = 2x - 24 x = 25
Answer: C) 25 years
Question: A sum of money becomes double itself in 6 years at simple interest. How many times will it become 10 years at the same rate?
A.2 1/3
B.3 1/3
C.2 1/4
D.3 1/4
Answer: B.3 1/3
Explanation: P ---- 2P ---- 6 years3 1/3 P ---- 10 years Answer: B
Question: Pipe A fills a tank in 12 minutes. Pipe B can fill the same tank 3 times as fast as pipe A. If both the pipes are kept open when the tank is empty, how many minutes will it take to fill the tank?
A.4 mins
B.6 mins
C.5 mins
D.3 mins
Answer: D.3 mins
Explanation: A's rate is 1/12 and B's rate is 1/4.
The combined rate is 1/12 + 1/4 = 1/3
The pipes will fill the tank in 3 minutes.
The answer is D.
Question: Three pairs of siblings, each pair consisting of one girl and one boy, are randomly seated at a table. What is the probability that all three girls are seated on the left of their boy siblings?
A.1/2
B.1/4
C.1/6
D.1/8
Answer: D.1/8
Explanation: Notice that we need a girl to be to the left of her sibling, but not necessarily right to the left of him (meaning that if B and G are siblings, then GB arrangement as well as for example G*B arrangement is possible).
Now, the probability that one particular sibling is seated that way is 1/2 (a girl can be either to the left of her sibling or to the right), the probability that two siblings are seated that way is 1/2*1/2 and the probability that all three siblings are seated that way is 1/2*1/2*1/2=1/8.
Answer: D.
Question: Holly,Paul,Anne and Jim are rehearsing a dance routine. How many different ways can you arrange the 4 dancers in a line if Anne must be first or second
A.11
B.12
C.13
D.14
Answer: B.12
Explanation: Anne first: three others follow in any order; 3P3 = 3! ways = 6
Anne 2nd: three other positions assigned in 3!ways = 6 ways.
TOTAL: 12 possible arrangements
Answer B
Question: There are 25 students in a class. Find the numbers of ways in which a committee of 3 students is to be formed?
A.1250
B.1800
C.2300
D.3256
Answer: C.2300
Explanation: Required number of ways = 25C3 = 25*24*23 / 6 = 2300
Answer is C