RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: A hemispherical bowl is made of 0.5 cm thick steel. Inner radius of the bowl is 4 cm. The volume of steel used in making the bowl is
A.55.83 cm3
B.56.83 cm3
C.113.67 cm3
D.58.83 cm3
Answer: B.56.83 cm3
Explanation: inner r= 4
outer R=4.5
formula= 2/3*22/7(R^2-r^2)
(2/3) * (22/7) *(4.5*4.5*4.5 - 4*4*4)
=56.83
ANSWER:B
Question: 7 people average age is 30. youngest person age is 4. find average of the people when youngest was born.
A.23
B.24
C.25
D.26
Answer: D.26
Explanation: average age of people =30
so have total age =210
before 7 years we have to deduct each person age by seven years 210-32=182
so average age would be 182/7=26
ANSWER:D
Question: A tradesman by means of his false balance defrauds to the extent of 20%? in buying goods as well as by selling the goods. What percent does he gain on his outlay?
A.13%
B.14%
C.44%
D.66%
Answer: C.44%
Explanation: g% = 20 + 20 + (20*20)/100
= 44%
Answer: C
Question: Who come next in the series ?
JAZ, LEX, NIV, POT
A.RUR
B.QUR
C.RUS
D.SUR
Answer: A.RUR
Explanation: 1st letter increases by 2
J+2=L, L+2=N,N+2=P, P+2=R
2nd letter increases by 4 for 1st 2 words, nd inc by 6 for next 2 words
A+4=E, E+4=I,I+6=O, O+6=U
3rd letter decreases by 2
Z-2=X, X-2=V, V-2=T, T-2=R
So the next word is RUR
ANSWER:A
Question: A ball is bought for Rs.400 and sold at a gain of 25% find its selling price?
A.A)Rs.480/-
B.B)Rs.490/-
C.C)Rs.500/-
D.D)Rs.520/-
Answer: C.C)Rs.500/-
Explanation: 100 % ------> 400 (100 * 4 = 400)
125 % ------> 500 (125 * 4 = 500)
Selling price = Rs.500/-
C
Question: A no. leaves a remainder 3 on division by 14, and leaves a remainder k on division by 35. How many possiblevalues can k take?
A.3
B.5
C.8
D.9
Answer: B.5
Explanation: A number leaves a remainder of 3 on division by 14, or it can be written as 14n + 3
On division by 70, the possible remainders can be 3, 17 (3 + 14), 31 (3 + 28), 45 (3 + 42), or 59 (3 + 56). The number can be of the form
70n + 3
70n + 17
70n + 31
70n + 45
70n + 59
Now, we need to divide this number by 35
70n + 3 divided by 35, the remainder will be 3.
70n + 17 divided by 35, the remainder will be 17.
70n + 31 divided by 35, the remainder will be 31.
70n + 45 divided by 35, the remainder will be 10.
70n + 59 divided by 35, the remainder will be 24.
On division by 35, the possible remainders are 3, 17, 31, 10 or 24. There are 5 possible remainders
Correct Answer: 5
B
Question: When sold at a 60% discount, a sweater nets the merchant a 35% profit on the wholesale cost at which he initially purchased the item. By what % is the sweater marked up from wholesale at its normal retail price?
A.20%
B.40%
C.50%
D.70.38%
Answer: D.70.38%
Explanation: we should be careful about what are we measuring % on/what is the base..
let the Marked up price =100..
Selling price= 100-60%of 100=40..
profit= 35%..
therefore the wholesale purchase cost= x.... 1.35x=40
or x=29.62...
marked price was 100 so ...
so answer is 70.38%..
D
Question: The total age of A and B is 16 years more than the total age of B and C. C is how many years younger than A?
A.16
B.24
C.C is elder than A
D.Data inadequate
Answer: A.16
Explanation: Solution
[(A+B) - (B+C)]	= 16
â€¹=â€ºA - C
= 16.
Answer A
Question: Find the number of ways of arranging the letters of the word "MATERIAL" such that all the vowels in the word are to come together?
A.1448
B.1440
C.1478
D.1477
Answer: B.1440
Explanation: In the word, "MATERIAL" there are three vowels A, I, E.
If all the vowels are together, the arrangement is MTRL'AAEI'.
Consider AAEI as one unit. The arrangement is as follows.
M T R L A A E I
The above 5 items can be arranged in 5! ways and AAEI can be arranged among themselves in 4!/2! ways.
Number of required ways of arranging the above letters = 5! * 4!/2!
= (120 * 24)/2 = 1440 ways.
Answer: B
Question: a+b=4,ab=3,find the sum of receiprocals of a and b
A.4/3
B.3/4
C.5/3
D.3/5
Answer: A.4/3
Explanation: 1/a+1/b=a+b/ab,
so 1/a+1/b=a+b/ab
=4/3
ANSWER:A
Question: An oil cylinder was 3/4th full. When THREE bottles of oil is poured into it, it is 4/5th full. How many bottles of oil
can the full cylinder hold?
A.60
B.15
C.40
D.30
Answer: A.60
Explanation: (4/5 -3/4) cylinder is filled by 3 bottles
0.8 -0.75 = 0.05 cylinder is filled by 3 bottles
1 cylinder is filled by 3/0.05 = 60 bottles
ANSWER:A
Question: A wooden box of dimensions 8 m x 7 m x 6 m is to carry rectangularboxes of dimensions 8 cm x 7 cm x 6 cm. The maximum number ofboxes that can be carried in the wooden box, is
A.9800000
B.1000000
C.7500000
D.1200000
Answer: B.1000000
Explanation: Explanation: Number = (800*700*600)/8*7*6 = 1000000 Answer: B
Question: Due to construction, the speed limit along an 9-mile section of highway is reduced from 55 miles per hour to 35 miles per hour. Approximately how many minutes more will it take to travel along this section of highway at the new speed limit than it would have taken at the old speed limit ?
A. 5
B. 7
C. 10
D. 15
Answer: B. 7
Explanation: 9/35 - 9/55 = 9/5 * ( 11 - 7)/77
= 9/5 * 4/77 * 60 min
= 9 * 12 * 4/77
= 432/77 ~ 5.6
Answer - B
Question: The largest number of four digits exactly divisible by 77 is
A.9768
B.9933
C.9988
D.9944
Answer: B.9933
Explanation: Explanation: Find the remainder when 10000 is divided by 77. Then subtract that remainder from 10000.
77) 10000 (12
77
230
154
760
693
67
So 10000 â€“ 67 = 9933 is exactly divisible by 77.
ANSWER IS B
Question: There are 280 doctors and nurses at a hospital. If the ratio of doctors to nurses is 5 to 9, how many nurses are at the hospital?
A.165
B.170
C.175
D.180
Answer: D.180
Explanation: The number of nurses at the hospital is (9/14)*280=180.
The answer is D.
Question: At the end of the day, February 14th, a florist had 150 roses left in his shop, all of which were red, white or pink in color and either long or short-stemmed. A third of the roses were short-stemmed, 20 of which were white and 15 of which were pink. The percentage of pink roses that were short-stemmed equaled the percentage of red roses that were short-stemmed. If none of the long-stemmed roses were white, what percentage of the long-stemmed roses were red?
A.50%
B.25%
C.250%
D.75%
Answer: A.50%
Explanation: R + W + P = 150
S + L = 150
1/3 * 150 = 50
Short-Stemmed White = 20
Short-Stemmed Pink = 15
=> Short-Stemmed Red =15
15/P = 15/R
=> R = P
So Total Long Stemmed = 100
And Long Stemmed Red + Long Stemmed Pink = 100
So Long Stemmed Red/Long Stemmed = ?
Total White = 20 (As no Long stemmed white)
=> R + R + 20 = 150
=> R = 130 and R = 65
Long Stemmed R = 65 - 15 = 50
So Long Stemmed Red/R = 50/100 = 50%
Answer - A
Question: The price of 2 saris and 4 shirts is Rs. 1600. With the same money one can buy 1 saree and 6 shirts. If one wants to buy 12 shirts, how much shall he have to pay ?
A.Rs. 2400
B.Rs. 2490
C.Rs. 2500
D.Rs. 2550
Answer: A.Rs. 2400
Explanation: Let the price of a saree and a shirt be Rs. x and Rs. y respectively.
Then, 2x + 4y = 1600 .... (i)
and x + 6y = 1600 .... (ii)
Divide equation (i) by 2, we get the below equation.
=> x + 2y = 800. --- (iii)
Now subtract (iii) from (ii)
x + 6y = 1600 (-)
x + 2y = 800
----------------
4y = 800
----------------
Therefore, y = 200.
Now apply value of y in (iii)
=> x + 2 x 200 = 800
=> x + 400 = 800
Therefore x = 400
Solving (i) and (ii) we get x = 400, y = 200.
Cost of 12 shirts = Rs. (12 x 200) = Rs. 2400.
A
Question: One pipe can fill a tank three times as fast as another pipe. If together the two pipes can fill the tank in 36 minutes, then the slower pipe alone will be able to fill the tank in
A.144 mins
B.140 mins
C.136 mins
D.132 minw
Answer: A.144 mins
Explanation: Explanation:
Let the slower pipe alone fill the tank in x minutes
then faster will fill in x/3 minutes.
Part filled by slower pipe in 1 minute = 1/x
Part filled by faster pipe in 1 minute = 3/x
Part filled by both in 1 minute =
1/x+3/x=1/36
=>4/x=1/36
x=36∗4=144mins
Option A
Question: 7 points are marked on a straight line and another 6 points are marked on a second straight line with no points in common. How many triangles can be constructed with vertices from among the above points?
A.281
B.91
C.168
D.196
Answer: A.281
Explanation: Solution: select 2 from 7 and one from 6 + select 2 from 6 and 1 from 7
7C2*6C1 + 6C2*7C1
= 281
Answer : A
Question: 40 men shake hands with each other. Maximum no of handshakes without cyclic handshakes.
A.780
B.200
C.210
D.220
Answer: A.780
Explanation: or, if there are n persons then no. of shakehands = nC2 = 40C2 = 780
ANSWER:A
Question: Find the C.I. on a sum of Rs.10000 for 6 months at 20% per annum, interest being compounded halfyearly?
A.3010
B.2010
C.1000
D.3100
Answer: C.1000
Explanation: C.I.= 10000(11/10)^1-10000
= 1000
Answer: C
Question: A music store has 90 different CD's. If an average price is $12 per CD and 20 of the most expensive ones are $20 each, what is the average price of the remaining CD's?
A.8.33
B.8.75
C.9.23
D.9.71
Answer: D.9.71
Explanation: The sum of the prices of all CD's is (90 * $12 = $1,080).
The sum of the prices of the most expensive CD's is $400. So, ($1,080 - $400 = $680) is left for 70 remaining CD's. Thus the average price is (frac{$680}{70} = $9.71)
Question: Find the value of 2 x [(3.6 x 0.48 x 2.50) / (0.12 x 0.09 x 0.5)]
A.800
B.500
C.900
D.1600
Answer: D.1600
Explanation: Answer
2 x [(3.6 x 0.48 x 2.50) / (0.12 x 0.09 x 0.5)]
= 2 x [(36 x 48 x 250) / (12 x 9 x 5)]
= 2 x 4 x 4 x 50 = 1600
Correct Option: D
Question: While camping, 3 people are to be seated around a stool. two seating arrangement are considered different only when the position of the people are different relative to each other. what is the total number of possible seating arrangement for the group?
A.a.2
B.b.10
C.c.8
D.d.32
Answer: A.a.2
Explanation: for 3 people seating arrangement around a circular stool = (3-1)!
= 2!
= 2*1
= 2
OA is A
Question: In what time will a railway train 40 m long moving at the rate of 36 kmph pass a telegraph post on its way?
A.5 sec
B.4 sec
C.3 sec
D.6 sec
Answer: B.4 sec
Explanation: T = 40/36 * 18/5 = 4 sec
Answer: B
Question: The speeds of 3 trains in the ratio 2:6:16 The ratio between time taken by them to travel the same distance is?
A.6:4:3
B.1:2:3
C.24:8:3
D.26:5:2
Answer: C.24:8:3
Explanation: Ratio of time taken is = 1/2 : 1/6 : 1/16 = 24:8:3
Answer is C
Question: Crazy Eddie has a key chain factory. Eddie managed to decrease the cost of manufacturing his key chains while keeping the same selling price, and thus increased the profit from the sale of each key chain from 20% of the selling price to 50% of the selling price. If the manufacturing cost is now $50, what was it before the decrease?
A.$20
B.$40
C.$50
D.$80
Answer: D.$80
Explanation: cost+profit=income (selling price)
profit now = 0.5x or x-50
0.5x=x-50
50=0.5x
x=100$ is selling price
so, profit before was 0.2*100=20$
cost=100-20=80$
ANSWER:D
Question: On increasing the number of lines in a page by 80, they become 240. What is the % of increase in the no. of lines in the page?
A.30%
B.40%
C.50%
D.70%
Answer: C.50%
Explanation: Explanation : Number of pages increased = 80
Now , the number of pages of book = 240
Number of pages of the books before increase = 240 – 80 = 160
% increase in the number of pages in the book = 80 160
x 100% = 50%
C
Question: A customer asks the clerk for a paintbrush and a bucket of whitewash for a total price of B dollars. If the paintbrush costs 100 cents less than twice the price of a bucket of whitewash, what is the price of half a bucket of whitewash in dollars?
A.(B + 200)/2.
B.(B + 2)/6.
C.(2B + 200)/3.
D.(B + 2)/3.
Answer: A.(B + 200)/2.
Explanation: P = 2w - 200
thus total price in cents as given should be
2w-200 +w = 100B
3w - 200 = 100 B
3w = 100 B+200
3w =b+2 (in dollars)
w/2 = (b+2)/6
Ans:A
Question: The compound ratio of 2/3, 6/7, 1/3 and 1/8 is given by?
A.1/49
B.1/42
C.1/09
D.1/77
Answer: B.1/42
Explanation: 2/3 * 6/7 * 1/3 * 1/8
= 1/42
Answer: B
Question: Eight people are planning to share equally the cost of a rental car. If one person withdraws from the arrangement and the others share equally the entire cost of the car, then the share of each of the remaining persons increased by:
A.1/7
B.2/7
C.3/7
D.4/7
Answer: A.1/7
Explanation: Original share of 1 person = 1/8
New share of 1 person = 1/7
Increase = (1/7 - 1/8	= 1/56)
Therefore, Required fraction = (1/56)/(1/8)	= (1/56)x (8/1)	= 1/7
Answer is A.
Question: A retailer bought a machine at a wholesale price of $90 and later on sold it after a 10% discount of the retail price. If the retailer made a profit equivalent to 20% of the whole price, what is the retail price r of the machine?
A.	81
B.	100
C.	120
D.	135
Answer: C.	120
Explanation: Since the wholesale price was $90 and the profit was 20% of the wholesale price ([.2][90] = $18), the retail price would have to be above $108, but not that much greater than that.
Let's start by TESTing Answer C: $120....
If.....
Retail Price r= $120
10% discount off = $120 - (.1)(120) = 120 - 12 = 108
20% profit on wholesale price = 90 + (.2)(90) = 90 + 18 = 108
These two numbers MATCH, so this MUST be the answer!
Final Answer:
[Reveal]Spoiler:
C
Question: A certain Social Security recipient will receive an annual benefit of $12,000 provided he has annual earnings of $9,360 or less, but the benefit will be reduced by $1 for every $3 of annual earnings over $9,360. What amount of total annual earnings would result in a 60 percent reduction in the recipient's annual Social Security benefit? (Assume Social Security benefits are not counted as part of annual earnings.)
A.$15,360
B.$17,360
C.$18,000
D.$23,760
Answer: D.$23,760
Explanation: For every $3 earn above $9360, the recipient loses $1 of benefit.
OR
For every $1 loss in the benefit, the recipient earns $3 above $9360
If earning is; 9360+3x
Benefit = 12000-x
Or the vice versa
If benefit is 12000-x, the earning becomes 9360+3x
He lost 50% of the benefit;
Benefit Received= 12000-0.6*12000 = 12000-7200
x=4800
Earning becomes 9360+3x=9360+3*4800=23760
Ans:D
Question: The smallest value of n, for which 2n+3 is not a prime number, is
A.4,5
B.3,4
C.2,6
D.5,6
Answer: B.3,4
Explanation: (2Ã—1 + 3) = 5.
(2Ã—2 + 3) = 7.
(2Ã—3 + 3) = 9.
(2Ã—4 + 3) = 15.
which is not prime , n=3,4.
ANSWER:B
Question: The workforce of Company X is 60% female. The company hired 24 additional male workers, and as a result, the percent of female workers dropped to 55%.How many employees did the company have after hiring the additional male workers?
A.160
B.220
C.288
D.360
Answer: C.288
Explanation: Let's xx be total quantity of employees
0.6x=females before adding men
0.55(x+24)=females after adding men
as quantity of women doesn't change we can make an equation:
0.6x=0.55(x+24)
0.05x=13.2
x=264 - this is quantity of employees before adding 24 men
So after adding it will be 288
Answer is C
Question: On the number line, the number p is twice as many units from -2 as -2 is from 7. If p is less than –2, what is the value of p ?
A.–20
B.–10
C.–6
D.10
Answer: A.–20
Explanation: Distance between -2 and 7 = 9
Since number p is twice as many units from -2 as -2 is from 7
, therefore p can be -20 Since , p is less than -2 ,
the value of p = -20
Answer A
Question: There are 4 boys and 2 girls. In how many ways can they be seated in a row so that all the 4boys do not sit together?
A.450
B.330
C.576
D.712
Answer: C.576
Explanation: Total number of persons = 4+2 = 6
they can be seated in a row in 6! ways
Treat 4boys as 1 so we have 3 people can be arranged in 3! ways
4boys can be arranged among themselves in 4! ways
Required number of ways = 6!-4!*3! = 576
Answer is C
Question: Meg and Bob are among the 7 participants in a cycling race. If each participant finishes the race and no two participants finish at the same time, in how many different possible orders can the participants finish the race so that Meg finishes ahead of Bob?
A.24
B.30
C.2520
D.90
Answer: C.2520
Explanation: Total # of ways the race can be finished is 7!. In half of the cases Meg finishes ahead of Bob and in other half Bob finishes ahead of Meg. So, ways Meg to finish ahead of Bob is 7!/2=2520.
Answer: C.
Question: A, B and C rents a pasture for Rs.870. A put in 12 horses for 8 months, B 16 horses for 9 months and 18 horses for 6 months. How much should C pay?
A.270
B.978
C.267
D.166
Answer: A.270
Explanation: 12*8 :16*9 = 18*6
8: 12: 9
9/29 * 870 = 270
Answer:A
Question: A man bought 10 crates of mangoes for $40 total. If he lost 2 of the crates, at what price would he have to sell each of the remaining crates in order to earn a total profit of 20 percent of the total cost?
A.$6
B.$8
C.$10
D.$12
Answer: A.$6
Explanation: As given, after lost, the remaining 8 crates total cost = $40
So, 1 crate cost = 40/8 = 5
To get 20% profit, 1 crate cost should be = 5+5*20/100 =$6
Answer : A
Question: One ton has 2100 pounds, and one pound has 16 ounces. How many packets containing wheat weighing 16 pounds and 4 ounces each would totally fill a gunny bag of capacity 13 tons?
A. 1680
B. 1700
C. 2350
D. 2500
Answer: A. 1680
Explanation: 16 pounds and 4 ounces= 16*16 + 4 = 260 ounces.
13 tons = 13*2100 pound = 13*2100*16 ounces.
Hence the answer is (13*2100*16)/260 = 1680.
Answer: A.
Question: The average of first 10 even numbers is?
A.226
B.27
C.27
D.11
Answer: D.11
Explanation: Sum of 10 even numbers = 10 * 11 = 110
Average = 110/10 = 11
Answer: D
Question: If a rectangular billboard has an area of 117 square feet and a perimeter of 44 feet, what is the length of each of the shorter sides?
A.4
B.7
C.8
D.9
Answer: D.9
Explanation: This question can be solved algebraically or by TESTing THE ANSWERS.
We're told that a rectangle has an area of 117 and a perimeter of 44. We're asked for the length of one of the SHORTER sides of the rectangle.
Since the answers are all INTEGERS, and the area is 117, the shorter side will almost certainly be less than 10 (since 10x10 = 100, but we're NOT dealing with a square). Answer B (7) does NOT divide evenly into 117, so the correct answer is
Let's TEST Answer D: 9
IF...
The shorter side = 9...
The area = 117....117/9 = 13 = the longer side
Perimeter = 9+9+13+13 = 44
D
Question: A certain sum becomes Rs. 20720 in four years and 24080 in six years at simple interest. Find sum and rate of interest?
A.14%
B.12%
C.11%
D.22%
Answer: B.12%
Explanation: Let the interest for one year be x.
As amount = Principal + Interest, we have
P + 4x = 20720 --- (1) ; P + 6x = 24080 --- (2)
Solving the equations (1) and (2), we can get
P = Rs. 14000 and x = Rs. 1680
Interest for one year on Rs. 14000 is Rs. 1680
So, R = (100 * 1680)/(14000 * 1) = 12% p.a.
Answer:B
Question: The distance between Delhi and Mathura is 120 kms. A starts from Delhi with a speed of 20 kmph at 7 a.m. for Mathura and B starts from Mathura with a speed of 25 kmph at 8 p.m. from Delhi. When will they meet?
A.40.00 a.m.
B.10.13 a.m.
C.12.00 a.m.
D.18.00 a.m.
Answer: B.10.13 a.m.
Explanation: Explanation:
D = 120 â€“ 20 = 100
RS = 20 + 25 = 45
T = 100/45 = 2 hours 13 minutes
8 a.m. + 2 hours 13 minutes = 10:13 a.m.
Answer: Option B
Question: A tyre has two punctures. The first puncture alone would have made the tyre flat in 8 minutes and the second alone would have done it in 6 minutes. If air leaks out at a constant rate, how long does it take both the punctures together to make it flat ?
A.3 1/5min
B.3 2/5min
C.3 3/7min
D.3 4/5min
Answer: C.3 3/7min
Explanation: Explanation:
Do not be confused, Take this question same as that of work done question's. Like work done by 1st puncture in 1 minute and by second in 1 minute.
Lets Solve it:
1 minute work done by both the punctures =
(1/8+1/6)=(7/24)
So both punctures will make the type flat in
(24/7)mins=3 3/7mins
Option C
Question: Jack and Lee walk around a circular track. It takes Jack and Lee respectively 6 and 10 minutes
to finish each lap. They start at the same time, at the same point on the track, and walk in the
same direction around the track. After how many minutes will they be at the same spot again
(not necessarily at the starting point) for the first time after they start walking?
A.15
B.16
C.30
D.32
Answer: A.15
Explanation: Experimenting with the numbers in turn, dividing 6 into 15 and 10 into 15, we get
answers one whole number apart, so they are together again at 15 minutes.
correct answer A
Question: Husband has prepared for a candle light dinner on the honeymoon for his wife. While they were having the dinner, a strong breeze flew through the open window and four candles out of ten were extinguished. After that, the husband closed the window.
How many candles were left in the end?
A.4
B.6
C.8
D.2
Answer: A.4
Explanation: A
Four
As the window was closed it is obvious that the six candles that were not extinguished were lit till they melted away entirely. Thus only four candles that were extinguished remain at the end.
Question: A part of certain sum of money is invested at 9% per annum and the rest at 15% per annum, if the interest earned in each case for the same period is equal, then ratio of the sums invested is?
A.4:6
B.4:9
C.5:3
D.4:1
Answer: C.5:3
Explanation: 15:9
= 5:3
Answer: C
Question: A pair of articles was bought for $50 at a discount of 30%. What must be the marked price of each of the article?
A.$25
B.$17.50
C.$29.65
D.$35.95
Answer: B.$17.50
Explanation: S.P. of each of the article = 50/2 = $25
Let M.P = $x
70% of x = 25
x = 25*.7 =$17.50
Answer is B
Question: A completes a work in 4 days and B complete the same work in 8 days. If both of them work together, then the number of days required to complete the work will be
A.8 days
B.9 days
C.2.67 days
D.12 days
Answer: C.2.67 days
Explanation: If A can complete a work in x days and B can complete the same work in y days, then, both
of them together can complete the work in x y/ x+ y days
Therefore, here, the required number of days = 4 × 8/ 12 = 2.67 days.
Answer : C
Question: A shopping cart contains only apples, oranges, and pears. If there are three times as many oranges as apples, and four times as many pears as oranges, then the apples are equivalent to what fraction of the pears?
A.1/6
B.1/8
C.1/12
D.1/4
Answer: C.1/12
Explanation: O = 3A
P = 4O = 12A
A = P/12
The answer is C.
Question: The speed at which a man can row a boat in still water is 15 kmph. If he rows downstream, where the speed of current is 3 kmph, what time will he take to cover 120 metres?
A.18
B.24
C.17
D.12
Answer: B.24
Explanation: Speed of the boat downstream = 15 + 3 = 18 kmph
= 18 * 5/18 = 5 m/s
Hence time taken to cover 120 m = 120/5 = 24 seconds.
Answer: B
Question: John works at a science lab that conducts experiments on bacteria. The population of the bacteria multiplies at a constant rate, and his job is to notate the population of a certain group of bacteria each hour. At 1 p.m. on a certain day, he noted that the population was 1,000 and then he left the lab. He returned in time to take a reading at 4 p.m., by which point the population had grown to 216,000. Now he has to fill in the missing data for 2 p.m. and 3 p.m. What was the population at 3 p.m.?
A.72,000
B.48,000
C.50,000
D.36,000
Answer: D.36,000
Explanation: let the rate be x, then population of the bacteria after each hour can be given as 1000, 1000x, 1000(x^2), 1000(x^3)
now population at 4pm =216,000
thus we have 1000(x^3) = 216,000 =216
thus x=6
therefore population at 3pm = 1000(36) = 36,000
Answer : D
Question: A boat moves downstream at the rate of 1 km in 5 mins & upstream at the rate of 4 km/hour. What is the velocity of the current?
A.2 km/hr
B.4 km/hr
C.8 km/hr
D.10 km/hr
Answer: B.4 km/hr
Explanation: Speed downstream = 1(560)=12 km/hr
Speed upstream =41 = 4 km/hr
velocity of the current =12(12−4)=4 km/hr
B
Question: A trained covered x km at 40 kmph and another 2x km at 20 kmph. Find the average speed of the train in covering the entire 3x km.
A.18 kmph
B.17 kmph
C.24 kmph
D.19 kmph
Answer: C.24 kmph
Explanation: Total time taken = x/40 + 2x/20 hours
= 5x/40 = x/8 hours
Average speed = 3x/(x/8) = 24 kmph
Answer:C