I am a number. I am a common multiple of 4, 5, 6, and 7. I am less than 10. What number am I?
zero
or, -420k for any positive integer k
To find the common multiple of 4, 5, 6, and 7 that is less than 10, we can start by listing out the multiples of each number until we find a number that is common to all of them.
For 4: 4, 8
For 5: 5, 10
For 6: 6, 12
For 7: 7, 14
Looking at the lists, we can see that the only number common to all of them and less than 10 is 4. Therefore, 4 is the number you are referring to.