Question

18. The ratio of the ages of A and B is 7:1. 4 years ago, the ratio of their ages was 19:1. What is the present age of A?

Answer 1

Answer:

Age of A = 42 years

Step-by-step explanation:

Given that-

The ratio of ages of A and B = 7 : 1

Let Age of A = 7x years

and age of B = x years

Before 4 years-

Age of A = 7x - 4

Age of B = x - 4

Ratio of the ages of A and B = 19 : 1

$\dfrac{7x-4}{x-4} = \dfrac{19}{1}$

By cross multiplication-

$(7x - 4) = 19(x - 4)$

7x - 4 = 19x - 76

19x - 7x = -4 + 76

12x = 72

$x = \dfrac{72}{12}$

x = 6

Age of A = 7x

               = 7 × 6

Age of A = 42 years