Aptitude and Reasoning Questions

Q:

Three number are in the ratio of 3 : 4 : 5 and their L.C.M. is 2400. Their H.C.F. is:

A) 40 B) 80
C) 120 D) 200
 
Answer & Explanation Answer: A) 40

Explanation:

Let the numbers be 3x, 4x and 5x.

 

Then, their L.C.M. = 60x.

 

So, 60x = 2400 or x = 40.

 

 The numbers are (3 x 40), (4 x 40) and (5 x 40).

 

Hence, required H.C.F. = 40.

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301 94361
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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371 93558
Q:

It was Sunday on Jan 1, 2006. What was the day of the week Jan 1, 2010?

A) Monday B) Friday
C) Sunday D) Tuesday
 
Answer & Explanation Answer: B) Friday

Explanation:

On 31st December, 2005 it was Saturday. 

Number of odd days from 2006 to 2009 = (1 + 1 + 2 + 1) = 5 days. 

 

On 31st December 2009, it was Thursday.

Thus, on 1st Jan, 2010 it is Friday

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456 92046
Q:

Two cards are drawn at random from a pack of 52 cards.what is the probability that either both are black or both are queen?

A) 52/221 B) 55/190
C) 55/221 D) 19/221
 
Answer & Explanation Answer: C) 55/221

Explanation:

We have n(s) =52C2 52 = 52*51/2*1= 1326. 

Let A = event of getting both black cards 

     B = event of getting both queens 

A∩B = event of getting queen of black cards 

n(A) = 52*512*1 = 26C2 = 325, n(B)= 26*252*1= 4*3/2*1= 6  and  n(A∩B) = 4C2 = 1 

P(A) = n(A)/n(S) = 325/1326;

P(B) = n(B)/n(S) = 6/1326 and 

P(A∩B) = n(A∩B)/n(S) = 1/1326 

P(A∪B) = P(A) + P(B) - P(A∩B) = (325+6-1) / 1326 = 330/1326 = 55/221

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278 91927
Q:

The average of runs of a cricket player of 10 innings was 32. How many runs must he make in his next innings so as to increase his average of runs by 4 ?

A) 76 B) 79
C) 85 D) 87
 
Answer & Explanation Answer: A) 76

Explanation:

Average = total runs / no.of innings = 32 

So, total = Average x no.of innings = 32 x 10 = 320.

 

Now increase in avg = 4runs. So, new avg = 32+4 = 36runs 

Total runs = new avg x new no. of innings = 36 x 11 = 396 

Runs made in the 11th inning = 396 - 320 = 76

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348 91473
Q:

Find the odd man out.

41, 43, 47, 53, 61, 71, 73, 81

A) 41 B) 61
C) 71 D) 81
 
Answer & Explanation Answer: D) 81

Explanation:

Each of the numbers except 81 is a prime number.

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119 91064
Q:

The last day of a century cannot be

A) Monday B) Wednesday
C) Tuesday D) Friday
 
Answer & Explanation Answer: C) Tuesday

Explanation:

ke

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703 88164
Q:

The value of a machine depreciates at the rate of 10% every year. It was purchased 3 years ago. If its present value is Rs. 8748, its purchase price was :

A) 10000 B) 12000
C) 14000 D) 16000
 
Answer & Explanation Answer: B) 12000

Explanation:

Purchase price = Rs.87481-101003 = Rs. [8748 * (10/9) * (10/9 )* (10/9)] = Rs.12000

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585 87793