Answer:
9 gal/day
Explanation:
We are given 1 cup per 10 minutes. You can always change the way an expression looks without changing its value if you multiply it by 1. But here we need to change the units. So the 1 we're multiplying is:
1gal/16cups or
60min/1hr or
24hr/1day
See image. We can set it up to cancel the units we don't want and get the units we do want.
see image.