Aptitude and Reasoning Questions

Q:

There are 10 Letters and 10 correspondingly 10 different Address. If the letter are put into envelope randomly, then find the Probability that Exactly 9 letters will at the Correct Address ?

A) 1/10 B) 1/9
C) 1 D) 0
 
Answer & Explanation Answer: D) 0

Explanation:

As we know we have 10 letter and 10 different address and one more information given that exactly 9 letter will at the correct address....so the remaining one letter automatically reach to their correct address
P(E) = favorable outcomes /total outcomes
Here favorable outcomes are '0'.
So probability is '0'.

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Filed Under: Probability
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Bank Clerk , Bank PO

5 9537
Q:

Two positions of a block are shown below: When six is at the bottom, what number will be at the top?

A) 1 B) 2
C) 4 D) 5
 
Answer & Explanation Answer: D) 5

Explanation:

From figures (i) and (ii) we conclude that the number 1, 2, 3 and 4 appear adjacent to 6. Thus, the number 5 will appear opposite 6. Therefore, when six is at the bottom, then 5 will be at the top.

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Filed Under: Cubes and Dice

47 9532
Q:

Ifab=45andbc=1516, then c2-a2c2+a2 is :

A) 7/5 B) 7/25
C) 7/125 D) 7
 
Answer & Explanation Answer: B) 7/25

Explanation:

ab×bc=45×1516=34=16-916+9

 

=725

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Filed Under: Simplification

7 9522
Q:

A man said to his son, "I was two-thirds of your present age when you were born". IIf the present age of the man is 48 years, find the present age of the son.

Answer

Let the Present age of the son be P, which means he was born P years ago.At the time the son was born, the age of the man was : (48 - P). So, according to the statement made by the man, his age when the son was born should be equal to 2/3 of P.


Therefore, 


Solving, we get P = 28.8 years; which is the present age of the son.

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Subject: Problems on Ages

10 9516
Q:

Find the cash realised by selling Rs. 2440, 9.5% stock at 4 discount (brokerage 1/4 %)

A) 2000 B) 2298
C) 2290 D) 2289
 
Answer & Explanation Answer: B) 2298

Explanation:

By selling Rs. 100 stock , cash realised = Rs.100-4-14=Rs.3834  

 

By selling Rs. 2400 stock, cash realised =Rs.3834*1100*2400 = Rs 2298.

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Filed Under: Stocks and Shares

12 9510
Q:

Find the remainder when 1234 x 1235 x 1237 is divided by 8.

A) 4 B) 2
C) 0 D) 6
 
Answer & Explanation Answer: D) 6

Explanation:

When we divide 1234 by 8, remainder is 2

When we divide 1235 by 8, remainder is 3

When we divide 1237 by 8, remainder is 5

---> 2 x 3 x 5 = 30 

As 30 will not be the remainder because it is greater than 8,

when 30 divided by 8, remainder = 6.

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Filed Under: Numbers
Exam Prep: CAT
Job Role: Bank PO

7 9505
Q:

Find the least number with which 16200 should be multiplied, to make it a perfect cube ?

A) 45 B) 48
C) 360 D) 36
 
Answer & Explanation Answer: A) 45

Explanation:

16200 = 23×34×52

 

A perfect cube has a property of having the indices of all its prime factors divisible by 3.

 

Required number = 32×5 = 9x5 = 45.

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Filed Under: Problems on Numbers
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6 9502
Q:

A box contains 4 different black balls, 3 different red balls and 5 different blue balls. In how many ways can the balls be selected if every selection must have at least 1 black ball and one red ball ?

A) 24 - 1  

B) 2425-1   

C) (24-1)(23-1)25   

D) None 

A) A B) B
C) C D) D
 
Answer & Explanation Answer: C) C

Explanation:

It is explicitly given that all the 4 black balls are different, all the 3 red balls are different and all the 5 blue balls are different. Hence this is a case where all are distinct objects.

 

Initially let's find out the number of ways in which we can select the black balls. Note that at least 1 black ball must be included in each selection.

 

Hence, we can select 1 black ball from 4 black balls
or 2 black balls from 4 black balls.
or 3 black balls from 4 black balls.
or 4 black balls from 4 black balls.

 

Hence, number of ways in which we can select the black balls

 

= 4C1 + 4C2 + 4C3 + 4C4
= 24-1 ........(A)

 

Now let's find out the number of ways in which we can select the red balls. Note that at least 1 red ball must be included in each selection.

 

Hence, we can select 1 red ball from 3 red balls
or 2 red balls from 3 red balls
or 3 red balls from 3 red balls

 

Hence, number of ways in which we can select the red balls
= 3C1 + 3C2 + 3C3
=23-1........(B)

 

Hence, we can select 0 blue ball from 5 blue balls (i.e, do not select any blue ball. In this case, only black and red balls will be there)
or 1 blue ball from 5 blue balls
or 2 blue balls from 5 blue balls
or 3 blue balls from 5 blue balls
or 4 blue balls from 5 blue balls
or 5 blue balls from 5 blue balls.

 

Hence, number of ways in which we can select the blue balls
= 5C0 + 5C1 + 5C2 + … + 5C5
= 25..............(C)

 

From (A), (B) and (C), required number of ways
=  2524-123-1

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Filed Under: Permutations and Combinations
Exam Prep: GATE , CAT , Bank Exams , AIEEE
Job Role: Bank PO , Bank Clerk

3 9498