Question

A’s present age is to B’s present age as 8 : 7. 27 years ago their ages were 5 : 4. Find their present ages.

Answer 1

Let A’s present age = 8x

Let B’s present age = 7x

27 years ago:

A’s age = 8x − 27

B’s age = 7x − 27

`(8x - 27)/(7x - 27) = 5/4`

⇒ 4(8x − 27) = 5(7x − 27)

⇒ 32x − 108 = 35x − 135

⇒ 32x − 35x = −135 + 108

⇒ −3x = −27

⇒ x = 9

A’s present age = 8x

= 8 × 9

= 72

B’s present age = 7x

= 7 × 9

= 63