The ratio of the present age of A, B and C is 4:5:3 respectively. If 5 years ago, the sum of the age of A, B and C together is 81, then find the difference between the present age of B and C?
A. 24 years
B. 36 years
C. 20 years
D. 16 years
E. None of these
Sol:
Let the present age of A = 4x
And the present age of B = 5x
And the present age of C = 3x
The sum of the present age of A, B and C
together = 81 + 5 * 3 = 96 years
The present age of B = 96 * 5x/(4x + 5x + 3x) =
96 * 5x/(4x + 5x + 3x) = 96 * 5x/12x = 40 years
The present age of C = 96 * 3x/(4x + 5x + 3x) =
96 * 3/12x = 24 years
Required difference = 40 – 24 = 16 years
