The lowest common multiple is the smallest (non-zero) multiple that is a multiple of 2 or more numbers.

Multiples of 3 are: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, ...

Multiples of 5 are: 5, 10, 15, 20, 25, 30, 35, 40, 45, ...

Notice that both 15 and 30 are common multiples.

Solution: 15 is the lowest common multiple of 3 and 5.

The numbers 3 and 5 do not have any common prime factors.

The lowest common multiple of the two is the smallest number that is a multiple of 3 as well as 5.

This is equal to 3*5 = 15

15 is the lowest common multiple of 3 and 5