7 years ago, Samir was 3 times as old as Deepak. In 4 years, Samir will be twice as old as Deepak. What is Deepak's present age?

7 years ago:

Let Deepak be x.

Deepak = x

Samir = 3x

Now (7 years later):

Deepak = x + 7

Samir = 3x + 7

In 4 years time:

Deepak = x + 7 + 4 = x + 11

Samir = 3x + 7 + 4 = 3x + 11

Samir is twice as old as Deepak:

⇒ 2 (x + 11) = 3x + 11

Solve x:

2 (x + 11) = 3x + 11

2x + 22 = 3x + 11

3x - 2x = 22 - 11

x = 11

*Remember the x that we define was Deepak's age 7 years ago.

Find Present Age:

Deepak = x + 7 = 11 + 7 = 18

Samir = 3x + 7 = 3 (11) + 7 = 40

Answer: Deepak is 18 years old.

3D+11=2D+22

D+11=22

D=11

D = Deepaks age 7 years ago so

11+7=18, his age now