Aptitude and Reasoning Questions

Let the age of the youngest child is 'X' years.
Then the child elder than the yongest is 'X + 3' yrs
Since each have 3yrs difference upto 5 children
And given that
=> X + X+3 + X+6 + X+9 + X+12 = 50
=> 5X + 30 = 50
=> X = 4 yrs.

Given a secret is told to 3 persons in 3 minutes.
And if the process continues with each person saying 3 other persons,
In 30 minutes => the rocess for 10 times because each person time is 3 minutes.
Required number of persons = 3 + 32 + 33 + .... + 39 + 310

Now it forms a geometric progression,

Sum to n terms is S = arn - 1r - 1

Here a = 3, r = 3

 
=> 59048 x 3 /2

= 88572.

Perimeter = Distance covered in 8 min. = (12000/60) * 8 = 1600m 

Let length = 3x metres and breadth = 2x metres.  

Then, 2(3x + 2x) = 1600 or x = 160.  

Length = 480 m and Breadth = 320 m.

Area = (480 x 320) = 153600 

Given A & B in partnership

A Invests 116000 for 12 months 

=> A's share = 116000 x 12 = 13,92,000

B Invests for 6 months

=> B's share = 144000 x 6 = 8,64,000

Their Ratio = 1392 : 864 = 29 : 18

Let the Annual profit = P

Given B's share = Rs. 9000

=> 18/47 x P = 9000

=> P = 9000 x 47/18

=> P = 23,500

Hence, Overall profit = P = Rs. 23,500

End of first year     :  10000 x (3/5) = Rs. 6000
End of second year :  6000 x (3/5) = Rs. 3600
End of third year    :  3600 x (3/5) = Rs. 2160

We know the formula for calculating

The compound interest C = P1 + r100n - 1 where P = amount, r = rate of interest, n = time

Here P = 5000, r1 = 10, r2 = 20

Then $$\begin{gathered} C = 65001 + 101002 x 1 + 201002 - 1 \\ = 6500 x 18562500 \\ = 65 x 185625 \end{gathered}$$

C = Rs. 4826.