Question 760980
No he won't.

The difference between their ages will always be only 120 days. 120 days, expressed as a proportion of the elder boy's age is 0.5 now. 

As they grow older, this proportion will only decrease.

Think of it this way - this proportion is a fraction expressed as 

{{{120/age of older boy}}}

The denominator of this fraction will keep increasing as they grow older, and the numerator is fixed. So the fraction will keep decreasing.

Since this fraction will keep decreasing and never be equal to 0.5 again, the first boy will never be as old as the second boy ever again.

:)