Just 1.
The number that both 7 and 8 can go into evenly is 56.
7 and 31 go into 217 evenly.
The number 7
The number is 112 and its multiples.
1, 7, and 49.
3.5 you multiply it by 2
It is: 210
It is: 252
168
Just 1.
They will all divide into 280 evenly with no remainder
1, 3, 7, 21.