Question

7 years ago, the ages (in years) of a and b were in the ratio 4:5 and 7 years hence they will be in the ratio 5:6. The present age of b is:

Answer 1

Let 7 yr ago, ages of A and B are 4x yr and 5x yr, respectively.

Then, present age of A = 4x + 7 and present age of B = 5x + 7

Now, according to the question,

4x+7+75x+7+7=564x+7+75x+7+7=56

24x + 84 = 25x + 70

x = 14

Hence, B's present age = 5 x 14 + 7= 77 yr