Question

The present age of A and B are in the ratio 7:5. Ten years hence, the ratio of their ages will be 9:7. Find the present ages of A:B?

Answer 1

Let the age of A be 7x and that of B = 5x
$\frac{7x+10}{5x+10} = \frac{9}{7}$
7(7x+10) = 9(5x+10)
49x+70 = 45x+90
4x = 20
x=5
Present age of A = 5x7 = 35
Present age of B = 5x5 = 25

Answer 2

Let the age of A be 7x and that of B = 5x

\frac{7x+10}{5x+10} = \frac{9}{7}

7(7x+10) = 9(5x+10)

49x+70 = 45x+90

4x = 20

x=5

Present age of A = 5x7 = 35

Present age of B = 5x5 = 25

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