What is the LCM of 38 20 and 28?

Answer 1

Factor out each number into primes to get:

38 = 2 * 19

20 = 2² * 5

28 = 2² * 7

Count the maximum number of distinct primes for all of these values. For instance, if 20 and 28 both have the maximum number of "2" 2, then write out 2². If one number has a prime factor while the rest of the number doesn't, then write out that prime factor. Following these steps, we have this product:

2² * 5 * 19 * 7

= 4 * 5 * 7 * 19

= 2660

So that is the LCM of the given numbers.