Enigma for two friends?

36 is divisible by 1, 2, 4, 6, 9, 18 and 36. There are several way to take 3 numbers that will multiply to 36, but only two ways to have numbers that will also add to the same total, that is 2, 2 and 9 (product 36, sum 13) and 1, 6 and 6 (product 36, sum also 13). Why the same total? Because the mathematician could not decide from the total, since he evidently knows he is riding bus #13. But he was told the oldest has blue eyes, so there is only one oldest kid (as opposed to 6 year old twins), so the oldest kid is 9 and there are 2 year old twins; so 9, 2 and 2 is the age of the kids.