Question

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

Answer 1

present age of a=x
present age of b=y
present age of c=z

given
$\frac{x - 3 + y - 3}{2} = 18$


and
$\frac{x - 3 + y - 3 + z}{3} = 22$


now by solving both equation we will get
z=66-36
so age of c is 30 years

Answer 2

30 years is the answer