The sum of the present ages of Sushmita and her daughter Ishita is 55 years. Ten years from now, Sushmita will be twice as old as Ishita. How old is Ishita now?

Explanation

1. 01

   Let Ishita be $d$; Sushmita is $55 - d$.

2. 02

   In 10 years: $65 - d = 2(d + 10)$.

3. 03

   $65 - d = 2d + 20$, so $3d = 45$ and $d = 15$.

4. 04

   Check: in 10 years they are 50 and 25.