by Nasim

(Bangladesh )

Average age of Dipu and Apu is 22 years. Average age of Dipu and Tipu is 24 years. Age of Dipu is 21 years. What are the ages of Apu, and tipu ?

Let 21 be Dipu's age

Let y be Apu's age

Let z be Tipu's age

Since the average age of Dipu and Apu is 22 years, we get

(21 + y)/2 = 22

Since the average age of Dipu and Tipu is 24 years, we get

(21 + z)/2 = 24

All we need to do now is to simplify the equations by getting rid of the denominator of 2.

For (21 + y)/2 = 22, just multiply both sides by 2.

we get 21 + y = 44

21 + y = 44

Subtract 21 from both sides

21 - 21 + y = 44 - 21

y = 23

For (21 + z)/2 = 24, just multiply both sides by 2.

we get 21 + z = 48

21 + z = 48

Subtract 21 from both sides

21 - 21 + z = 48 - 21

z = 27

Apu's age is 23

Tipu's age is 27