The ages of three sisters are consecutive numbers with the sum of 39. How old is the OLDEST sister?

Question

Need answer as fast as possible.

Answer 1

n = age of youngest

n + 1 = age of next youngest

n + 2 = age of oldest

n + (n + 1) + (n + 2) = 39

Can you solve for n, then get n+2 and finish from here?