Aptitude and Reasoning Questions

Q:

If 20% of a = b, then b% of 20 is the same as :

A) 4% of a B) 6% of a
C) 8% of a D) 10% of a
 
Answer & Explanation Answer: A) 4% of a

Explanation:

20% of a = b 

=> (20/100) * a = b 

 b% of 20 =(b/100) x 20 = [(20a/100)  / 100] x 20= 4a/100 = 4% of a.

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1309 156120
Q:

Insert the missing number.

7, 26, 63, 124, 215, 342, (....)

A) 391 B) 421
C) 481 D) 511
 
Answer & Explanation Answer: D) 511

Explanation:

Numbers are (23 - 1), (33 - 1), (43 - 1), (53 - 1), (63 - 1), (73 - 1) etc.

So, the next number is (83 - 1) = (512 - 1) = 511.

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402 151588
Q:

8 litres are drawn from a cask full of wine and is then filled with water. This operation is performed three more times. The ratio of the quantity of wine now left in cask to that of the water is 16 : 65. How much wine the cask hold originally?

A) 18 litres B) 24 litres
C) 32 litres D) 42 litres
 
Answer & Explanation Answer: B) 24 litres

Explanation:

Let the quantity of the wine in the cask originally be x litres

 
Then, quantity of wine left in cask after 4 operations =x1-8x4litres

 

x1-8x4x = 1681  

 

 1-8x4=234 

 

x=24

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583 144293
Q:

Find the odd man out.

2, 5, 10, 17, 26, 37, 50, 64

A) 50 B) 37
C) 26 D) 64
 
Answer & Explanation Answer: D) 64

Explanation:

(1*1)+1 , (2*2)+1 , (3*3)+1 , (4*4)+1 , (5*5)+1 , (6*6)+1 , (7*7)+1 , (8*8)+1

But, 64 is out of pattern.

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113 143666
Q:

A clock is set right at 8 a.m. The clock gains 10 minutes in 24 hours will be the true time when the clock indicates 1 p.m. on the following day?

A) 48 min. past 12. B) 46 min. past 12.
C) 45 min. past 12. D) 47 min. past 12.
 
Answer & Explanation Answer: A) 48 min. past 12.

Explanation:

Time from 8 a.m. on a day to 1 p.m. on the following day = 29 hours. 

24 hours 10 min. of this clock = 24 hours of the correct clock. 

1456 hrs of this clock = 24 hours of the correct clock. 

29 hours of this clock = 24*6145*29 hrs of the correct clock 

= 28 hrs 48 min of the correct clock. 

Therefore, the correct time is 28 hrs 48 min. after 8 a.m. 

This is 48 min. past 12.

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698 143620
Q:

Out of 7 consonants and 4 vowels, how many words of 3 consonants and 2 vowels can be formed?

A) 25200 B) 52000
C) 120 D) 24400
 
Answer & Explanation Answer: A) 25200

Explanation:

Number of ways of selecting (3 consonants out of 7) and (2 vowels out of 4) = (7C3*4C2

= 210. 

 

Number of groups, each having 3 consonants and 2 vowels = 210. 

 

Each group contains 5 letters. 

 

Number of ways of arranging 5 letters among themselves = 5! = 120 

 

Required number of ways = (210 x 120) = 25200.

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269 142802
Q:

If each side of a square is increased by 25%, find the percentage change in its area?

A) 65.25 B) 56.25
C) 65 D) 56
 
Answer & Explanation Answer: B) 56.25

Explanation:

let each side of the square be a , then area = a2 

As given that The side is increased by 25%, then 

New side = 125a/100 = 5a/4 

 

New area = 5a42  

 

Increased area= 25a216-a2 

 

Increase %=9a2/16a2*100  % = 56.25%

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957 140102
Q:

A, B and C can do a piece of work in 24 days, 30 days and 40 days respectively. They began the work together but C left 4 days before the completion of the work. In how many days was the work completed?

A) 11 days B) 12 days
C) 13 days D) 14 days
 
Answer & Explanation Answer: A) 11 days

Explanation:

One day's work of A, B and C = (1/24 + 1/30 + 1/40) = 1/10.

C leaves 4 days before completion of the work, which means only A and B work during the last 4 days.

Work done by A and B together in the last 4 days = 4 (1/24 + 1/30) = 3/10.

Remaining Work = 7/10, which was done by A,B and C in the initial number of days. 

Number of days required for this initial work = 7 days. 

Thus, the total numbers of days required = 4 + 7 = 11 days.

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544 140071