Find out the age of children
Since the sum of the ages must be equal to 13, we have 14 possibilities (excluding cases where any child is 0 years old, in which case the product would be 0, which is not Jarbas's age). Of these 14 possibilities, only 2 cases (1,6,6 and 2,2,9) in which the product gives the same result (36). Since Jarbas is missing data, he must necessarily be 36 years old.
So the answer is (2,2,9) for there is a greater son, according to the statement of the problem.
Back to statement