A: I have three sons. The product of their ages is 36 and the sum of their ages is the number of the bus we are sitting in.

     B: Of course I know the number of the bus, but I can't still guess their ages. Can you give one more detail?

     A: The biggest child has blue eyes

     B: Now I get it! Their ages are...

Knowing that A and B are very intelligent. Can you explain how B found their ages and tell me what is the number of the bus?