There are four children. One of them is one year older than the other. The product of the four ages is 360. How old is the biggest one?
360 = 2 × 2 × 2 × 3 × 3 × 5 = 3 × 4 × 5 × 6; a: the oldest of them is 6 years old
360 = 2 × 2 × 2 × 3 × 3 × 5 = 3 × 4 × 5 × 6; a: the oldest of them is 6 years old