Question

What number is a common multiple of 5 and 9

Answer 1

45

5 10 15 20 25 30 35 40 45

9 18 27 36 45

Answer 2

Common multiple is a number which is a multiple of two or more numbers which is common to two given numbers.
Example 5 and 9
5 = 0, 10, 15, 20, 25, 30, 35, 40, 45, 50
9 = 0, 9, 18, 27, 36, 45, 54, 63, 72, 81
The common multiple or the Least Common Multiple of the numbers 5 and 9 is 45.
The LCM or the Least Common Multiple of two or more numbers that is common to both given numbers like 5 and 9 which is 45.