What number is a common multiple of 5 and 9?

Solution:

The multiples that are common to two or more numbers are known as their common multiples.

Since 5 and 9 are co-prime numbers, their common multiple would be their product.

Hence,

5 × 9 = 45

Thus, 45 is a common multiple of 5 and 9.

What number is a common multiple of 5 and 9?

Summary:

45 is a common multiple of 5 and 9.