Asking what six multiples of fifteen are is the same as asking how many are in six groups of fifteen. To find this you need to multiply: 6X15= 90
30, 60, 90.
15
1 2 3 5 6 9 10 15 18 30 45
-11
141
30 = 1 x 30, 2 x 15, 3 x 10, 5 x 6
-15
6*6=36
6 and 1
1x6 2x3
4 and 11.
-5 and -10