5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100
The multiples of 5 that are also multiples of 6 are multiples of their LCM. The LCM of 5 and 6 is 30, so the question becomes which multiples of 30 are less than 100? The solution is the numbers: 30, 60, 90
20
17,34,51,68,85
The multiples of 3 up to 30 are: 3,6,9,12,15,18,21,24,27,30.The multiples of 5 up to 30 are: 5,10,15,20,25,30.The only common multiples are 15 and 30.The LCM is: 30
40 and all its multiples...
' 1 ' is a factor of every whole number . . . . . 100 of them' 2 ' is a factor of every even number . . . . . 50 of them' 3 ' has 33 multiples up to 100 . . . . . 33 of them' 4 ' has 25 multiples up to 100 . . . . . 25 of them' 5 ' has 20 multiples up to 100 . . . . . 20 of them' 6 ' has 16 multiples up to 100 . . . . . 16 of them' 7 ' has 14 multiples up to 100 . . . . . 14 of them' 8 ' has 12 multiples up to 100 . . . . . 12 of them' 9 ' has 11 multiples up to 100 . . . . . 11 of themTotal . . . . . . . . . . . . . . . . . . . . . . . . . 281 one-digit factors in all whole numbers 1 to 100 .
30, 60, 90
The multiples of 5 that are also multiples of 6 are multiples of their LCM. The LCM of 5 and 6 is 30, so the question becomes which multiples of 30 are less than 100? The solution is the numbers: 30, 60, 90
Since 10 is a multiple of 5, all multiples of 10 will also be multiples of 5. Test the theory. 30, 50, 100... All multiples of 10, and also of 5.
20
Just add 5 at a time, starting from 5 (or perhaps from 0): 0, 5, 10, etc.
60 and 42 have no common multiples under 100.
6,12,18,24,30,36,42,48,54,60,66,72,78,84,90,96
17,34,51,68,85
20,40,60,80,and 100
6 of them.
5,10,15,20,25,30,35,40,45,50,55,60