OK, so to solve this, we can use proportions.
You would set up 3/8 gallons over 1/4 an hour to x over 1 hour. But to make this easier let's do decimals.
0.375 x
--------- = --------
0.25 1
Now just cross multiply.0.375=0.25xAnd divide to get rid of the x1.5=x
So, it would leak 1.5 gallons of water in one hour! I hope you were able to understand this. Please ask any questions. ;)