RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: Pipe A fills a tank of capacity 700 liters at the rate of 40 liters a minute. Another pipe B fills the same tank at the rate of 30 liters a minute. A pipe at the bottom of the tank drains the tank at the rate of 20 liters a minute. If pipe A is kept open for a minute and then closed and pipe B is open for a minute and then closed and then pipe C is open for a minute and then closed and the cycle is repeated, when will the tank be full?
A.42 minutes
B.14 minutes
C.39 minutes
D.40 minutes 20 seconds
Answer: A.42 minutes
Explanation: In one cycle they fill 40+30-20 = 50 liters
700 = 50*n => n = 14
here n = number of cycles.
total time = 14*3 = 42 as in one cycle there are 3 minutes.
thus 42 minutes
ANSWER:A
Question: If x is divisible by 2 and 7, which of the following must divide evenly into x? I. 60 II. 32 III. 14
A.I,II only
B.I,III only
C.I only
D.III only
Answer: D.III only
Explanation: If x is divisible by 2,7 means it will be = or > 14, 28,42 etc...
That are not divisible by 60, 32.
So, the answer is D
Question: Ramu bought an old car for Rs. 42000. He spent Rs. 13000 on repairs and sold it for Rs. 66900. What is his profit percent?
A.17%
B.19%
C.18%
D.21.6%
Answer: D.21.6%
Explanation: Total CP = Rs. 42000 + Rs. 13000
= Rs. 55000 and SP
= Rs. 66900
Profit(%) = (66900 - 55000)/55000 * 100
= 21.6%
Answer: D
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 36 hours and 16 hours respectively. The ratio of their speeds is?
A.4:5
B.4:3
C.4:6
D.4:9
Answer: C.4:6
Explanation: Let us name the trains A and B.
Then, (A's speed) : (B's speed)
= √b : √a = √16 : √36 = 4:6
Answer:C
Question: Betty picked a number of pears, each of which she sold, canned, or poached. If she canned 30 percent more than she poached, and she poached 10 percent less than she sold. If there were a total of 614 pears, then how many pears did she sell?
A.190
B.200
C.210
D.220
Answer: B.200
Explanation: Let x be the amount of pears that she sold.
Then she poached 0.9x.
Then she canned 1.3*0.9x=1.17x.
The total amount of pears is x+0.9x+1.17x=3.07x
The fraction of pears that she sold is 1/3.07=100/307.
The number of pears she sold is (100/307)*614=200.
The answer is B.
Question: The second smallest prime number is?
A.67
B.71
C.73
D.21
Answer: A.67
Explanation: The second smallest prime number is 67.
A)
Question: If the length of an edge of cube M is four times the length of an edge of cube N, what is the ratio of the volume of cube N to the volume of cube M?
A.1/32
B.1/16
C.1/8
D.1/64
Answer: D.1/64
Explanation: The length of cube N = 1;
The length of cube M = 4;
The ratio of the volume of cube N to the volume of cube M = 1^3/4^3 = 1/64
Answer : D
Question: The number of permutations of the letters of the word 'REMEMBER' is?
A.7!/(2!)2 3!
B.8!/(2!)2 8!
C.8!/(8!)2 3!
D.8!/(2!)2 3!
Answer: D.8!/(2!)2 3!
Explanation: n items of which p are alike of one kind, q alike of the other, r alike of another kind and the remaining are distinct can be arranged in a row in n!/p!q!r! ways.
The letter pattern 'REMEMBER' consists of 8 letters of which there are 2R's, 3E's, 2M's and 1B.
Number of arrangements = 8!/(2!)2 3!
Answer: D
Question: The number 311311311311311311311 is:
A.divisible by 3 but not by 11
B.divisible by 11 but not by3
C.divisible by both 3 and 11
D.neither divisible by 3 nor by 11.
Answer: D.neither divisible by 3 nor by 11.
Explanation: Sum of digits= 35 and so it is not divisible by 3.
(Sum of digits at odd places)- (Sum of digits at even places)= 19-16=3, not divisible by 11.
So, the given number is neither divided by 3 nor by 11.
ANSWER:D
Question: During a two-week period, the price of an ounce of silver increased by 5 percent by the end of the first week and then decreased by 10 percent of this new price by the end of the second week. If the price of silver was x dollars per ounce at the beginning of the two-week period, what was the price, in dollars per ounce, by the end of the period?
A.0.945x
B.0.985x
C.0.995x
D.1.05x
Answer: A.0.945x
Explanation: The price at the end is 0.9(1.05x)=0.945x
The answer is A.
Question: Simple interest on a certain sum is 9 over 25 of the sum. Find the rate per cent and time, if both are equal.
A.8% and 8 years
B.6% and 6 years
C.10% and 10 years
D.6 % and 6 years
Answer: D.6 % and 6 years
Explanation: 9â„25 P = PÃ—RÃ—R/100
â‡’ R2 = 900â„25 â‡’ R^2 = 36 R= 6
Also, time = 6 years
Answer D
Question: if A=2^65 AND B=2^64+2^63.....+2^0
A.A is larger than B by 2^64 times
B.B is larger than A by 1
C.A is larger than B by 1
D.A is equal to B
Answer: C.A is larger than B by 1
Explanation: lets say A : 2^4=16 , B: 2^3+2^2+2^1+2^0 = 15 so A is larger than B by 1 always
ANSWER:C
Question: X, Y and Z together invested Rs.106000, X invested Rs.4000 more than Y, and Rs.10000 more than Z. what is the share of X out of annual profit of Rs.26500 ?
A.Rs.10000
B.Rs.10800
C.Rs.10500
D.Rs.11000
Answer: A.Rs.10000
Explanation: Let Z share be ‘a’ then
Y = a + Rs.6000 [as X investment is Rs.10000 more than Z, and Rs.4000 more than Y, then Y share more than Z by Rs.10000 – Rs.4000 = Rs.6000]
X = a + Rs.10000.
X + Y + Z = 3a + 16000 = Rs.106000.
3a = 106000 – 16000 = Rs.90000.
a = 90000 / 3 = Rs.30000.
therefore Z investment = Rs.30000.
Y = Rs.30000 + Rs.6000 = Rs.36000.
X = Rs.30000 + Rs.10000 = Rs.40000.
Ratio of shares X : Y : Z = 20 : 18 : 15 = [53 units].
Investment Ratio = Profit sharing Ratio.
X = 26500 × 20 / 53 = Rs.10000
Option A
Question: A trade analyst announced 10% reduction in the unit price of bike. As a result, the sales volume went up by 25%. What was the net effect on the sales revenue?
A.no change
B.decreases by 12.5%
C.increases by 12.5%
D.increases by 10%
Answer: C.increases by 12.5%
Explanation: Explanation :
Reduction of price = (100 -10)% = 90% = 0.9
Increase of sale = (100+25)% = 125% = 1.25
Total effect = 0.90X 1.25 = 112.5%, Increases by 12.5%
Answer : C
Question: 10, 50, 13, 45, 18, 38, ?.
What a number should replace the question mark?
A.34
B.27
C.25
D.46
Answer: C.25
Explanation: C
25
There are two alternate sequences: start at 10 and add 3, 5, 7;
start at 50 and deduct 5, 7, 9.
Question: Two trains are running in opposite directions in the same speed. The length of each train is 120 meter. If they cross each other in 4 seconds, the speed of each train (in km/hr) is
A.42
B.36
C.108
D.120
Answer: C.108
Explanation: Explanation:
Distance covered = 120+120 = 240 m
Time = 4 s
Let the speed of each train = v. Then relative speed = v+v = 2v
2v = distance/time = 240/4 = 60 m/s
Speed of each train = v = 60/2 = 30 m/s
= 30×36/10 km/hr = 108 km/hr
Answer: Option C
Question: In a college, 50% of total 400 Arts students are Locals. 25% of students from 100 Science students are locals and 85% of total 120 Commerce students are locals. What is the total percentage of locals from Arts, Science and Commerce.
A.322
B.340
C.333
D.327
Answer: D.327
Explanation: locals from Arts = 50% of 400 = 200
locals from Science = 25% of 100 = 25
locals from Commerce = 85% of 120 = 102
total locals = 200+25+102 = 327
D
Question: Of 5 employees, 3 are to be assigned an office and 2 are to be assigned a cubicle. If 3 of the employees are men and 2 are women, and if those assigned an office are to be chosen at random, what is the probability that the offices will be assigned to 2 of the men and 1 of the women?
A.1/3
B.2/5
C.1/2
D.3/5
Answer: D.3/5
Explanation: probability = Desired Outcomes/Total Outcomes
Event = Selection of 3 employees to assign office from 5 such that 2 are men and 1 is woman
Total Outcomes = Selection of any 3 employees from 5 employees = 5 C 3 = 10
Desired Outcomes = Selection of 2 Men from 3 Men AND selection of 1 woman from 2 Women. = (3 C 2) * (2 C 1) = 3*2 = 6
Probability = 6/10 --------> 3/5
ANSWER:D
Question: An outlet pipe can empty 2/3 rd of a cistern in 12 minutes. In 8 minutes, what part of the cistern will be emptied?
A.4/9
B.2/3
C.3/4
D.5/6
Answer: A.4/9
Explanation: 2/3 ---- 12
? ----- 8 ==> 4/9
ANSWER A
Question: A couple who own an appliance store discover that if they advertise a sales discount of 10% on every item in the store, at the end of one month the number of total items sold increases 20%. Their gross income from sales for one month increases by what percent?
A.2%
B.4%
C.5%
D.8%
Answer: D.8%
Explanation: Let List price of an item = 100
Discount on each item = 10%
Discounted price of an item = .9*100 = 90
If they advertise a sales discount of 10% on every item in the store, at the end of one month the number of total items sold increases 20%
Originally if 10 items were sold in a month , with the new discount 12 items will be sold
Original revenue = No of items* Price of an item = 10 * 100 = 1000
New revenue = 12 * 90 = 1080
Increase in gross income = 1080 - 1000 = 80
% increase in gross revenue = 80/1000 * 100% = 8%
Answer D
Question: Mohit sold an article for Rs. 18000. Had he offered a discount of 22% on the selling price, he would have earned a profit of 8%. What is the cost price of the article?
A.13000
B.27767
C.16688
D.26678
Answer: A.13000
Explanation: Let the CP be Rs. x.
Had he offered 22% discount, profit = 8%
Profit = 8/100 x and hence his SP = x + 8/100 x = Rs. 1.08x = 18000 - 22/100(18000) = Rs. 14040
=> 1.08x = 14040
=> x = 13000
\Answer: A
Question: The average age of three persons is 52 years. Their ages are in the proportion of 1:5:7. What is the age in years of the oldest one among them.
A.9 years
B.12 years
C.60 years
D.70 years
Answer: D.70 years
Explanation: Explanation:
Let the age of three persons be x, 5x, 7x
= 13x/3 = 52
x= 12 years
Answer: Option D
Question: The cost of 10 kg of apples is equal to the cost of 24 kg of rice. The cost of 6 kg of flour equals the cost of 2 kg of rice. The cost of each kg of flour is Rs.20.50. Find the total cost of 4 kg of apples, 3 kg of rice and 5 kg of flour?
A.777.4
B.877.4
C.577.4
D.477.4
Answer: B.877.4
Explanation: Let the costs of each kg of apples and each kg of rice be Rs.a and Rs.r respectively.
10a = 24r and 6 * 20.50 = 2r
a = 12/5 r and r = 61.5
a = 147.6
Required total cost = 4 * 147.6 + 3 * 61.5 + 5 * 20.5
= 590.4 + 184.5 + 102.5 = Rs.877.40
Answer: B
Question: If A is thrice as fast as B and together can do a work in 21 days. In how many days A alone can do the work?
A.36
B.42
C.28
D.54
Answer: C.28
Explanation: A’s one day’s work= 1/X
B’s one day’s work= 1/3x
A + B’s one day’s work= 1/x + 1/3x = 1/21
= 3+1/3x = 4/3x = 1/21
x = 21*4/3 = 28
ANSWER:C
Question: When n is divided by 5 the remainder is 3. What is the remainder when (n + 3)^2 is divided by 5?
A.0
B.1
C.2
D.3
Answer: B.1
Explanation: n = 5x+3, for some integer x
(n+3)^2=(5x+6)^2=5y+36, for some integer y
When we divide this by 5, the remainder is 1.
The answer is B.
Question: A team scored a total of 126 points. If each player on the team scored at least 14 points, then what is the greatest possible number of players on the team?
A.A)6
B.B)7
C.C)8
D.D)9
Answer: D.D)9
Explanation: 126/14=9 plus remainder.
The answer is D.
Question: The sale price sarees listed for Rs.400 after successive discount is 20% and 15% is?
A.297
B.272
C.342
D.762
Answer: B.272
Explanation: 400*(80/100)*(85/100)
= 272
Answer: B
Question: In how many ways a committee, consisting of 5 men and 6 women can be formed from 8 men and 10 women?
A.11760
B.266
C.5040
D.3000
Answer: A.11760
Explanation: Req no of ways = 8C5 * 10C6
=11760
ANSWER A
Question: P is three times as fast as Q and working together, they can complete a work in 14 days. In how many days can Q alone complete the work?
A.18 1/2 days
B.17 1/2 days
C.19 1/2 days
D.14 1/4 days
Answer: A.18 1/2 days
Explanation: P = 3Q
P + Q = 3Q + Q = 4Q
These 4Q people can do the work in 14 days, which means Q can do the work in 48 days.
Hence, P can do the work in 18 1/2 days.
Answer:A
Question: If an investor puts $800 in a savings account that earns 10 percent annual interest compounded semiannually, how much money will be in the account after one year?
A.$878
B.$880
C.$882
D.$884
Answer: C.$882
Explanation: 1.05*1.05*800=$882
The answer is C.
Question: There are 3 bags, in 1st there are 9 Mangoes, in 2nd 8 apples & in 3rd 6 bananas. There are how many ways you can buy one fruit if all the mangoes are identical, all the apples are identical, & also all the Bananas are identical?
A.648
B.432
C.23
D.2 to the power(23)-1
Answer: C.23
Explanation: Since bags are different so it should be 9+8+6=23
ANSWER:C
Question: How many three digits number can be formed by using the digits 1,2,3,4,5?
A.152
B.125
C.225
D.325
Answer: B.125
Explanation: Here the repetition of digits allowed. The unit place of the number can be filled in by any of the given numbers in 5 ways. Simillarly each one of the ten's and the hundred's place can be filled in 5 ways. Therefor the total number of required numbers =5*5*5 =125 Answer : B
Question: Can you please walk me through how to best approach this problem? Thanks
If #p# = ap^3+ bp – 1 where a and b are constants, and #-5# = 6, what is the value of #5#?
A.5
B.0
C.-8
D.-3
Answer: C.-8
Explanation: #p# = ap^3 + bp - 1
#-5# = 6
putting p = -5 in above equation
-125a -(5b +1) = 6 or
#-5# = (125a+5b+1) = -6
therefore 125a+5b = -7 .....(1
now putting p = 5
#5# = 125 a+5b - 1
using equation 1(125a+5b = -7)
#5# = -7-1 = -8
hence C
Question: Simple interest on a sum at 4% per annum for 2 years is Rs.80. The C.I. on the same sum for the same period is?
A.81.6
B.81.7
C.81.0
D.281.6
Answer: A.81.6
Explanation: SI = 40 + 40
CI = 40 + 40 + 1.6 = 81.6.Answer: A
Question: A 25 cm wide path is to be made around a circular garden having a diameter of 4 meters. Approximate area of the path is square meters is?
A.3.34 sq m
B.3.38 sq m
C.3.24 sq m
D.3.36 sq m
Answer: A.3.34 sq m
Explanation: Area of the path = Area of the outer circle - Area of the inner circle
= ∏{4/2 + 25/100}2 - ∏[4/2]2
= ∏[2.252 - 22] = ∏(0.25)(4.25) { (a2 - b2 = (a - b)(a + b) }
= (3.14)(1/4)(17/4)
= 53.38/16
= 3.34 sq m
Answer:A
Question: If the gross salary for first year is Rs. 45000 and an employee has two options to choose from for increment .Either he can opt for 4% yearly increase or Rs. 25000/- yearly increase on the gross salary. If an employee choose the first option, after how many years his salary will be more than the option two ?
A.15 years
B.16 years
C.17 years
D.18 years
Answer: D.18 years
Explanation: if initial annual gross salary = Rs. 450000/-
check when
450000+25000*n = 450*(1+4/100)^n
After 18 years
ANSWER:D
Question: A ranch has both horses and ponies. Exactly 5/7 of the ponies have horseshoes, and exactly 2/3 of the ponies with horseshoes are from Iceland. If there are 3 more horses than ponies, what is the minimum possible combined number of horses and ponies on the ranch?
A.33
B.37
C.41
D.45
Answer: D.45
Explanation: 5/7*P are ponies with horseshoes, so P is a multiple of 7.
2/3*5/7*P = 10/21*P are Icelandic ponies with horseshoes, so P is a multiple of 21.
The minimum value of P is 21. Then H = P+3 = 24.
The minimum number of horses and ponies is 45.
The answer is D.
Question: In 1986 the book value of a certain car was 2/3 of the original price, and in 1988 its book value was 1/2 of the original purchase price. By what percent did the book value for this car decrease from 1986 to 1988?
A.16 2/3 %
B.25 %
C.33 1/3 %
D.50%
Answer: B.25 %
Explanation: 1986; 2/3
1988; 1/2
% decrease = change/original*100
2/3−1/2 / 2/3∗100
1/6∗3/2∗100=14∗100=25
Answer: "B"
Question: A Bell Curve (Normal Distribution) has a mean of − 1 and a standard deviation of 1/8 . How many integer values Q are within three standard deviations of the mean?
A.0
B.1
C.3
D.6
Answer: B.1
Explanation: Got the question correctly -- the second item -- [highlight]bthe list of elements in the set is required.[/highlight] is not required.
With the new information, there is only one integer value (-1) that is between (-1.375, -0.625) i.e., falls within the three 3 SD range.B
Question: The ratio between the speeds of two trains is 7 : 8. If the second train runs 400 kms in 4 hours, then the speed of the first train is:
A.70 km/hr
B.75 km/hr
C.80 km/hr
D.87.5 km/hr.
Answer: D.87.5 km/hr.
Explanation: Let the speed of two trains be 7x and 8x km/hr.
Then, 8x = 400/4 = 100
Let the speed of two trains be 7x and 8x km/hr.
x = 100/8 = 12.5
Speed of first train = (7 x 12.5) km/hr = 87.5 km/hr.
Answer : D.
Question: Rahul's Mathematics test had 75 problems, 10 arithmetic, 30 algebra, 35 geometry problems.
Although he answered 70% of arithmetic, 40% of arithmetic and 60% of geometry problems correctly,
still he got less than 60% problems right. How many more questions he would have to answer more to get
passed
A.5
B.6
C.7
D.8
Answer: A.5
Explanation: Explanation:
Number of questions attempted correctly = (70% of 10 + 40% of 30 + 60% of 35)
= 7 + 12 + 21 = 40.
Questions to be answered correctly for 60% = 60% of total quations
= 60 % of 75 = 45.
He would have to answer 45 - 40 = 5
Answer: Option A
Question: A wheel that has 6 cogs is meshed with a larger wheel of 9 cogs. When the smaller wheel has made 21 revolutions, then the number of revolutions mad by the larger wheel is:
A.49
B.4
C.12
D.14
Answer: D.14
Explanation: Let the required number of revolutions made by larger wheel be x.
Then, More cogs, Less revolutions (Indirect Proportion)
9 : 6 :: 21 : x 9 * x = 6 x 21
x =	(6 x 21)/9
x = 14.
Answer is D.
Question: A soda machine sells both bottles and cans, and no other items. Bottles cost $1.50 each, while cans cost $0.75 each. If on one day, the soda machine sold 250 total beverages and yielded $315, how many more bottles than cans were sold?
A.60
B.80
C.90
D.115
Answer: C.90
Explanation: b+c=250_______(1)
1.5b+0.75c=315
2b+c=420_______(2)
(2)-(1)
b=170
c=80
b-c=170-80=90
ANSWER:C
Question: The probability that a visitor at the mall buys a pack of candy is 10%. If three visitors come to the mall today, what is the probability that exactly two will buy a pack of candy?
A.0.009
B.0.015
C.0.027
D.0.036
Answer: C.0.027
Explanation: One case is: candy - candy - no candy
The probability is 1/10*1/10*9/10 = 9/1000
There are 3 such cases, so we should multiply this probability by 3.
P(exactly 2 buy candy) = 9/1000 * 3 = 27/1000 = 0.027
The answer is C.
Question: A rope of which a calf is tied is increased from 12 m to 23 m, how much additional grassy ground shall it graze?
A.1222
B.1289
C.1210
D.1129
Answer: C.1210
Explanation: π (232 – 122)
= 1210
Answer:C
Question: A number increased by 40% gives 1680. The number is?
A.1680
B.1600
C.1200
D.1500
Answer: C.1200
Explanation: Formula = TOTAL=100% ,INCREASE = "+" DECREASE= "-"
A number means = 100 %
That same number increased by 40 % = 140 %
140 % -------> 1680 (140 Ã— 12= 1680)
100 % -------> 1200 (100 Ã— 12 = 1200)
Option 'C'
Question: A dishonest dealer professes to sell his goods at Cost Price but still gets 40% profit by using a false weight. What weight does he substitute for a kilogram?
A.714 1/7 grams
B.714 2/7 grams
C.714 8/3 grams
D.714 1/3 grams
Answer: B.714 2/7 grams
Explanation: If the cost price is Rs.100, then to get a profit of 40%, the selling price should be Rs.140.
If 140kg are to be sold, and the dealer gives only 100kg, to get a profit of 40%.
How many grams he has to give instead of one kilogram(1000 gm).
140 gm ------ 100 gm
1000 gm ------ ?
(1000 * 100)/140 = 714 2/7 grams.
Answer:B
Question: Set A contains all the even numbers between 2 and 50 inclusive. Set B contains all the even numbers between 62 and 110 inclusive. What is the difference between the sum of elements of set B and the sum of the elements of set A?
A.1500
B.3100
C.4400
D.6200
Answer: A.1500
Explanation: Each term in set B is 60 more than the corresponding term in set A.
The difference of the sums = 25 * 60 = 1500.
The answer is A.
Question: Each shelf of a bookcase contained 12 books. If the librarian took out 21 books and rearranged the remaining books so that all shelves but the last one contained 8 books and that last shelf contained 3 books, how many shelves does the bookcase have?
A.4
B.5
C.6
D.7
Answer: A.4
Explanation: Let x be the number of shelves.
12x - 21 = 8(x-1) + 3
4x = 16
x= 4
The answer is A.
Question: Lanya prepared 4 different letters to 4 different addresses. For each letter, she prepared one envelope with its correct address. If the 4 letters are to be put into the four envelopes at random, what is the probability that only one letter will be put into the envelope with its correct address?
A.1/24
B.1/8
C.1/4
D.1/3
Answer: D.1/3
Explanation: Total Lanya# of ways - 4! = 24.
Desired:
A-Mapped to the only correct address----------x 1 way only
B-Mapped to other two incorrect addresses - x 2 ways
C-Mapped to other two incorrect addresses - x 2 ways
D-Mapped to other two incorrect addresses - x 2 ways
Therefore, 1*2*2*2/24 = 1/3.?
Question: 10 years ago, the average age of a family of 4 members was 24 years. Two children having been born (with age diference of 2 years), the present average age of the family is the same. The present age of the youngest child is ?
A.1
B.7
C.3
D.9
Answer: C.3
Explanation: Total age of 4 members, 10 years ago = (24 x 4) years = 96 years.
Total age of 4 members now = [96 + (10 x 4)] years = 136 years.
Total age of 6 members now = (24 x 6) years = 144 years.
Sum of the ages of 2 children = (144 - 136) years = 8 years.
Let the age of the younger child be years.
Then, age of the elder child = years.
So,
Age of younger child = 3 years.
Answer: C
Question: If x+y=25 and x2y3 + y2x3=25, what is the value of xy?
A.1
B.2
C.3
D.4
Answer: A.1
Explanation: xy=1
As x+y=25
x2y3+y2x3=25
x2y2(y+x)=25
Substituting x+y
x2y2=1
xy=1
ANSWER:A
Question: A train moves fast a telegraph post and a bridge 264 m long in 8 sec and 20 sec respectively. What is the speed of the train?
A.79.4
B.79.0
C.79.5
D.79.2
Answer: D.79.2
Explanation: Let the length of the train be x m and its speed be y m/sec.
Then, x/y = 8 => x = 8y
(x + 264)/20 = y
y = 22
Speed = 22 m/sec = 22 * 18/5 = 79.2 km/hr.
Answer:D
Question: If 12 persons meet at a reunion and each person shakes hands exactly once with each of the others, what is the total number of handshakes?
A. 10•9•8•7•6•5•4•3•2•1
B. 10•10
C. 10•9
D. 66
Answer: D. 66
Explanation: We got #12 people who shake each other's hands once ==> a pair of 2
12!/10!2! = 12*11 / 2*1 = 66.
Hence answer D.
Question: A pupil's marks were wrongly entered as 79 instead of 45. Due to that the average marks for the class got increased by half. The number of pupils in the class is :
A.30
B.80
C.20
D.68
Answer: D.68
Explanation: Let there be x pupils in the class.
Total increase in marks = (X*1/2) = X/2.
X/2 = (79 - 45)
=> X/2 = 34
=> X = 68.
ANSWER:D
Question: A can do a piece of work in 40 days; B can do the same in 30 days. A started alone but left the work after 10 days, then B worked at it for 10 days. C finished the remaining work in 10 days. C alone can do the whole work in?
A.days
B.days
C.days
D.1/2 days
Answer: A.days
Explanation: Explanation:
10/40 + 10/30 + 10/x = 1
x = 24 days
Answer: A
Question: What will be the day of the week 15th August, 2010?
A.Sunday
B.Monday
C.Tuesday
D.Thursday
Answer: A.Sunday
Explanation: 15th August, 2010 = (2009 years + Period 1.1.2010 to 15.8.2010)
Odd days in 1600 years = 0
Odd days in 400 years = 0
9 years = (2 leap years + 7 ordinary years) = (2 x 2 + 7 x 1) = 11 odd days 4 odd days.
Jan. Feb. March April May June July Aug.
(31 + 28 + 31 + 30 + 31 + 30 + 31 + 15) = 227 days
227 days = (32 weeks + 3 days) 3 odd days.
Total number of odd days = (0 + 0 + 4 + 3) = 7 0 odd days.
Given day is Sunday.
Answer: Option A
Question: What must be added to each of the numbers 7, 11 and 19, so that the resulting numbers may be in continued proportion?
A.3
B.5
C.4
D.-3
Answer: D.-3
Explanation: Let X be the required number, then
(7 + X) : (11 + X) :: (11 +X) : (19 + X)
(7 + X) (19 + X) = (11 + X)2
X2 + 26X + 133 = X2 + 22X + 121
4X = - 12 or X = - 3
ANSWER:D