Question

Ruchika’s grandmother is five times as old as Ruchika. After 5 years, her grandmother will be four times as old as Ruchika will be then. Find the present age of Ruchika’s grandmother.

Answer 1

Step-by-step explanation:

Let Ruchika's present age be x years.

Grandmother's age = 5x

After 5 years,

Ruchika's age = x + 5 years

Grandmother's age = 4(x + 5) years

ATQ,

4(x + 5) = 5x + 5

4x + 20 = 5x + 5

5x - 4x = 20 - 5

x = 15

Ruchika's present age = 15 years

Grandmother's present age = 15 × 5 = 75 years