6
One third of 18 is 6. 6 goes into 18 three times - 6 + 6 = 12, 12 + 6 = 18.
The first six multiples of 3 are 3, 6, 9, 12, 15, and 18.
10/12 15/18 20/24 ect...10/12, 15/18, 20/24
-3 0 3 then 6 9 12 15 18 21 and so on ...
3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39 . . .
There are probably tens of such sets. Some are: 5, 6, 7, 7, 8, 11, 13, 14, 15, 16, 17, 18 5, 6, 7, 7, 7, 12, 12, 14, 15, 16, 17, 18 5, 6, 7, 7, 7, 12, 12, 14, 14, 16, 17, 18 5, 6, 7, 7, 7, 12, 12, 14, 14, 15, 17, 18 5, 6, 7, 7, 7, 12, 12, 14, 15, 15, 17, 18 5, 6, 7, 7, 7, 12, 12, 14, 15, 16, 16, 18 5, 6, 7, 7, 7, 12, 12, 14, 14, 16, 16, 18
EQ2
3 + 3 = 6 6 x 3 = 18 18 - 3 = 15 15 + 3 = 18
18/21 x 15 is 12 6/7
9.75
6 12 9 18 15 30 27 54 51