Question

Average age of A and B is 25 years.
Average are of Band C is 30 years and
average age of C and A is 35 years. What is the age of A?​

Answer 1

$a = x \\ \\ we \: take \: the \\ = > b = 10 \\ = > c = 20 \\ \\ (i) = > a + b = \\ = > x + 10 = 25 \\ = > x = 25 - 10 \\ = > x = 15 \\ \\ (ii)b + c = 30 \\ = > 10 + 20 = 30 \\ \\ (iii)c + a = 35 \\ 20 + 15 = 35 \\ \\ since \: \: a = x \\ x = 15$