The multiples of 13 that could be his age after 2 years.
13, 26, 39, 52, 65, 78, 91
If his age after 2 years was any of those, then after 1 year his age would be
12, 25, 38, 51, 64, 78, 90
The only one of those that's a multiple of 5 is 25.
Further checking 26, 2 less than 26 is 24, a multiple of 3.
So the answer is 24.
Edwin