What are the first three common multiples of three eight and nine?

Answer 1

8 and 9 are corpime, so their first common multiple is their product. The next common multiples are simply the multiples of that first multiple.

The first three common multiples are therefore 72, 144 and 216.

Answer 2

Simply write out the multiples of 8:

1 * 8 = 8

2 * 8 = 16

3 * 8 = 24

4 * 8 = 32

5 * 8 = 40

6 * 8 = 48

7 * 8 = 56

8 * 8 = 64

9 * 8 = 72

Then write out the multiples of 9:

1 * 9 = 9

2 * 9 = 18

3 * 9 = 27

4 * 9 = 36

5 * 9 = 45

6 * 9 = 54

7 * 9 = 63

8 * 9 = 72

So far we have two multiples:

36 and 72.

The last multiple will be left as an exercise for the reader. After all, if we do your homework for you, you won't learn.