Answer: 10 treats per seal, and there are 5 treats left.
Explanation:
The zookeeper has 85 treats, and want to divide them into seals, in such a way that the treats left is minimized,
Then we want to find the multiple of that is closer to 85 (from below)
We know that: 8*10 = 80 is a multiple of 8, and the next one is:
8*11 = 88, but this is larger than 85, so we discard this option.
Then we will divide 80 treats into 8 seals, and we will have:
85 - 80 = 5 treats left.
Then each one of the 8 seals gets:
80/8 = 10 treats.