Question

Find the least common multiple of 3 and 7

Answer 1

The LCM of two prime numbers is generally just their product, since they share no common factors.

3 and 7 are both prime numbers, so their LCM (least common multiple) is simply the numbers multiplied together. In this case, the LCM is thus 21.

Answer 2

Answer: 21

Step-by-step explanation: To find the least common multiple or lcm of 3 and 7, begin by finding the first few multiples of each number and comparing the lists.

Multiples of 3

1 × 3 = 3

2 × 3 = 6

3 × 3 = 9

4 × 3 = 12

5 × 3 = 15

6 × 3 = 18

7 × 3 = 21

Multiples of 7

1 × 7 = 7

2 × 7 = 14

3 × 7 = 21

Since 21 appears in both lists, we can stop here.

Therefore, the least common multiple of 3 and 7 is 21.