Question

3 years ago the average age of a and b was 18 years. with c joining them now the average age becomes 22 years. how old is c now?

Answer 1

a-3+b-3/2 =18
a+b-6=36
a+b=42
a+b+c/3= 22
a+b+c=66
substitute a+b=42 in above eqn
42+c=66
c=66-42
c=24
c is 24 years old

Answer 2

Hey mate!

Here's your answer!!
________________

Let the present age of A, B & C be the a, b, & c respectively.

Now we know that, 3 years ago, the average age of A and B was 18 years.

∴ (a - 3) + (b - 3)

= 2 × 18

= 36

Now, (a + b) = 42

Now, average age of A, B and C is...

∴22 a+b+c

= 3 × 22

= 66

The age of C is now (66 - 42) = 【24 years】
________________
$hope \: it \: helps \: you..$

✌ ✌ ✌