## Quantitative Aptitude Questions and Answers With Explanation (Practice set 16)

By Sahil Bansal | Views: 382

Q1:
Find the compound interest on Rs. 16,000 at 20% per annum for 9 months, compounded quarterly

A) 2422 B) 2522
C) 2622 D) 2722

Q2:
A man sitting in a train which is traveling at 50 kmph observes that a goods train, traveling in the opposite direction, takes 9 seconds to pass him. If the goods train is 280 m long, find its speed.?

A) 60 B) 62
C) 64 D) 65

Q3:
Three unbiased coins are tossed. What is the probability of getting at least 2 heads?

A) 1/4 B) 1/2
C) 3/4 D) 1/3

Q4:
50 men took a dip in a water tank 40 m long and 20 m broad on a religious day. If the average displacement of water by a man is 4 cu.m, then the rise in the water level in the tank will be:

A) 20 cm B) 25 cm
C) 35 cm D) 50 cm

Q5:
An error of 2% in excess is made while measuring the side of a square. The percentage of error in the calculated area of the square is:

A) 1.04 B) 2.04
C) 3.04 D) 4.04

Q6:
In a 1 km race, A beats B by 28 meters in 7sec. Find A's time over the course?

A) 5min,4sec B) 4min,3sec
C) 2min,3sec D) 3min,4sec

Q7:
The product of two co-prime numbers is 117. Their L.C.M  should be

A) 1 B) 117
C) Equal to their H.C.F D) cannot be calculated

Q8:
A certain sum of money amounts to Rs 1008 in 2 years and to Rs 1164 in 3 ½  years. Find the sum and the rate of interest.

A) 800, 14% B) 800, 13%
C) 800, 12% D) 800, 19%

Q9:
A certain number of men can finish a piece of work in 100 days. If there were 10 men less, it would take 10 days more for the work to be finished. How many men were there originally?

A) 75 B) 82
C) 100 D) 110

Q10:
A, B, C together can do a piece of work in 10 days. All the three started working at it together and after 4 days, A left. Then, B and C together completed the work in 10 more days. In how many days can complete work alone?

A) 25 B) 24
C) 23 D) 21

Explanation:

Principal = Rs. 16000; Time = 9 months =3 quarters;
Rate = 20% per annum = 5% per quarter.
Amount = Rs. [16000 x (1+(5/100))3] = Rs. 18522.
CJ. = Rs. (18522 - 16000) = Rs. 2522

Explanation:

Relative speed =280/9  m / sec = (280/9*18/5)  kmph = 112 kmph.
Speed of goods train = (112 - 50) kmph = 62 kmph.
Explanation:
Here S= {TTT, TTH, THT, HTT, THH, HTH, HHT, HHH}.
Let E = event of getting at least two heads = {THH, HTH, HHT, HHH}.
P(E) = n(E) / n(S)
= 4/8= 1/2

Explanation:

Total volume of water displaced =(4 x 50) cu.m = 200 cu.m
Rise in water level = (200/(40×20))=0.25m = 25cm

Explanation:

100 cm is read as 102 cm.
A1 = (100*100)Sq.cm
A2 = (102*102)Sq.cm
(A2 - A1) = 102x102−100x100 = (102 + 100) x (102 - 100) = 404 sq.cm.

Explanation:

B covers 28 meters in 7sec. So, B's time over the course = (7/28)*100 =250 sec.
Whereas A's time over the course = 250 -7 = 243 sec.
i.e A's time over the course is 4min, 3 sec.

Explanation:

H.C.F of co-prime numbers is 1. So, L.C.M = 117/1 =117

Explanation:

S.I. for 1 ½ years = Rs (1164 - 1008) = Rs 156 .
S.I. for 2 years = Rs (156 x 2/3 x 2)= Rs 208.
Therefore, Principal = Rs (1008 - 208) = Rs 800.
Now, P = 800, T= 2 and S.I. = 208.
Therefore, Rate = (100 x S.I.) / (P x T) = [ (100 x 208)/(800 x 2)]% = 13%

Explanation:

Originally let there be x men.
Fewer men, More days     (Indirect Proportion)
Therefore, (x-10) : x  :: 100 :110
=> (x - 10) * 110 = x * 100    => x= 110

Explanation:

(A+B+C) do 1 work in 10 days.
So (A+B+C)'s 1 day work=1/10 and as they work together for 4 days so work is done by them in 4 days=4/10=2/5
Remaining work=1-2/5=3/5
(B+C) take 10 more days to complete 3/5 of work. So( B+C)'s 1 day work=3/50
Now A'S 1 day work=(A+B+C)'s 1 day work - (B+C)'s 1 day work=1/10-3/50=1/25
A does 1/25 work in 1 day
Therefore 1 work in 25 days.