Question

The sum of reciprocals of rehman’s ages 3 years ago and 5 years from now is 1/3. Find his present age

Answer 1

His age is 7 years.

Explanation:

Let Rehman's present age be x years.

1 / (x - 3) + 1 /(x + 5) = 1/3

Multiply through by the LCD 3(x - 3)(x + 5):

3(x + 5) + 3(x - 3) = (x + 5)(x - 3)

3x + 15 + 3x - 9 = x^2 + 2x - 15

x^2 + 2x - 6x - 30 + 9 = 0

x^2 - 4x - 21 = 0

(x - 7)(x + 3) = 0

x = 7 (answer).