A is 2 years older than B and B is twice as old as C. If the sum of the ages of A, B and C be 27 years, then how old is B?

10 years

A is 2 years older than B

B is twice as old as C.

The sum of the ages of A, B and C be 27 years.

So,

let age of C be (x)

=> age of B = 2x

=> age of A = 2x + 2

=> x + 2x + 2x + 2 = 27

=> 5x = 25

So, x = 5

Thus, the age of B is 5 x2 = 10yrs old.