48
How about: 80
The number that both 7 and 8 can go into evenly is 56.
Both 7 and 16 can go into their least common multiple (LCM), which is 112. This means that any multiple of 112, such as 112, 224, or 336, can be evenly divided by both 7 and 16. Additionally, they can both go into any number that is a common multiple of both.
1, 2, 4, 8, 16.
1, 2, and 3 for both 16 and 30.
144
How about: 80
The number that both 7 and 8 can go into evenly is 56.
The number is 112 and its multiples.
1, 2, 4, 8, 16.
288
144
These numbers go evenly into both 800 and 160 evenly: 1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 80, 160.
1, 2, and 3 for both 16 and 30.
3 and 1 will go into both number evenly leaving no remainders.
80, among others.
They both will divide into 6 evenly