Provide your best answer for the following math problem. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The problem is: the sum of the present ages of two persons a and b is 60 . if the age of a is twice that of b , find the sum of their ages 5 years hence ?
70
a = 40 + 2b, sum in 5 years = 65 + 2b.