Question

The age of x and y is in the ratio 5:7.four years later their age will be in the ratio 3:4 Find their age

Answer 1

Let the present age of x and y be 5k and 7k.
Four years later, their ages will be 5k+4 and 7k+4
(5k+4 ) /(7k+4 )= 3 / 4
20k + 16 = 21k + 12
⇒ k = 4
Their ages are 20 and 28.