Aptitude and Reasoning Questions

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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253 82032
Q:

If each edge of a cube is increased by 50%, find the percentage increase in Its surface area

A) 125% B) 150%
C) 175% D) 110%
 
Answer & Explanation Answer: A) 125%

Explanation:

Let the edge = a cm   

So increase by 50 % = a + a/2 = 3a/2  

Total surface Area of original cube = 6a2  

TSA of new cube = 63a22 =69a24=  13.5a2   

Increase in area = 13.5a2-6a2 =7.5a2  

 7.5a2 Increase % =7.5a26a2×100 = 125%

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425 79146
Q:

A man spends 35% of his income on food, 25% on children's education and 80% of the remaining on house rent. What percent of his income he is left with ?

A) 6 % B) 8 %
C) 10 % D) 12 %
 
Answer & Explanation Answer: B) 8 %

Explanation:

Let the total income be x. 

Then, income left = (100 - 80)% of [100 -  (35 + 25)] % of x = 20% of 40% of x = [(20/100) * (40/100) * 100] % of x = 8 % of x.

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343 77819
Q:

A can do a piece of work in 10 days, B in 15 days. They work together for 5 days, the rest of the work is finished by C in two more days. If they get Rs. 3000 as wages for the whole work, what are the daily wages of A, B and C respectively (in Rs):

A) 200, 250, 300 B) 300, 200, 250
C) 200, 300, 400 D) None of these
 
Answer & Explanation Answer: B) 300, 200, 250

Explanation:

A's 5 days work = 50%  

B's 5 days work = 33.33% 

C's 2 days work = 16.66%     [100- (50+33.33)] 

Ratio of contribution of work of A, B and C = 50 : 3313 : 1623 = 3 : 2 : 1   

A's total share = Rs. 1500 

B's total share = Rs. 1000 

C's total share = Rs. 500  

 

A's one day's earning = Rs.300  

B's one day's earning = Rs.200  

C's one day's earning = Rs.250

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488 76944
Q:

Salaries of Ravi and Sumit are in the ratio 2:3. If the salary of each is increased by Rs. 4000, the new ratio becomes 40:57. What is Sumit's salary?

A) 38000 B) 46800
C) 36700 D) 50000
 
Answer & Explanation Answer: A) 38000

Explanation:

Let the original salaries of Ravi and Sumit be Rs. 2x and Rs. 3x respectively.
Then,
(2x+4000) / (3x+4000) = 40 / 57
⇒ 57 × (2x + 4000) = 40 × (3x+4000)
⇒ 6x = 68,000
⇒ 3x = 34,000
Sumit's present salary = (3x + 4000) = Rs.(34000 + 4000) = Rs. 38,000

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312 75714
Q:

A batsman makes a score of 87 runs in the 17th inning and thus increases his average by 3. Find his average after 17th inning?

Answer

Let the average after 7th inning = x


Then average after 16th inning = x - 3


16(x-3)+87 = 17x 


 x = 87 - 48 = 39

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543 75470
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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70 75303
Q:

A shopkeeper cheats to the extent of 10% while buying and selling, by using false weights. His total gain is.

A) 20% B) 21%
C) 22% D) 23%
 
Answer & Explanation Answer: B) 21%

Explanation:

Gain % = 100+common gain %2100-100%           

 

           =100+102100-100

 

            = 21%

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406 75164