Multiple choice

The average age of A and B is 24 years. If C were to replace A, the new average of B and C would become 23.5 years and if C were to replace B, then average age would be 22.5 years. What is the age of C?

  1. 22 years

  2. 21 years

  3. 26 years

  4. 20 years

  5. 24 years
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Average of A and B = 24 years

So, (A + B)/2 = 24

A + B = 48    -------------(1)

On replacing A with C,

(C + B)/2 = 23.5

C + B = 47   -------------(2)

On putting the value of B in equation (2), we get

C + 48 - A = 47

C - A = -1    ---------------(3)

Now, replacing B with C

(A + C)/2 = 22.5

A + C = 45 --------------(4) 

Now, on solving equations (3) and (4), we get

C = 22 years

Keep practicing — related questions