Let's turn these into decimals.
so, 10.
0.75
0.50=1/2
0.40
0.20=1/5
In order from least to greatest, these would be:
0.2, 0.4, 0.5, 0.75, 10
There were 15 gallons of water to begin with. hope this helps
Just add 32 + 33 = 65. 65 would be the minimum amount.