Question

Two numbers are in the ratio 5 : 7. If the sum of the numbers is 720, find the numbers.

Answer 1

Suppose that the numbers are 5x and 7x.
The sum of the numbers is 720.
i.e., 5x + 7x = 720
⇒ 12x = 720
⇒ x = 60

Hence, the numbers are (5 $\times$ 60 =) 300 and (7 $\times$ 60 =) 420.