Question

After $15$ years, Mary's age will be four times of her present age. Find her present age.

Answer 1

Let present age of Mary $=m$ years

After $15$ years, Mary's age $=(m+15)$ years

It is given that,

After $15$ years, Mary's age $=4m$

$\Rightarrow 4m=m+15$

$\Rightarrow 3m=15$

$\Rightarrow m=\frac{15}{3}$

$\Rightarrow m=5$

Therefore, Present age of Mary is $5$ years.