What is the least common multiple of 15 and 20?

Answer: 60

Step-by-step explanation:

Find the prime factor of 15

15 = 3 * 5

Find the prime factor of 20

20 = 4 * 5

Multiply each factor the greater number of times it occurs in steps i) or ii) above to find the lcm:

4 * 3 * 5

LCM = 60