10.- A survey taker goes to a house where he questions a woman:

Number of children? Three, she answers.

Ages? The product of their ages is 36 and the addition is the same as the number of this house.

The survey taker leaves but later he comes back and tells the woman that the information provided is not enough. The woman thinks and says: You are right, the older one studies piano.

This is enough for the survey taker to guess the children's age. What are their ages?