This is my best guess from memory
20*16=320
8*square root of 3=13.9
320+13.9=333.9
I can tell you the answer if you can tell me how much she was carrying before she dropped nine of them
2 1/4 = 9/4
(9/4)(8/5) = (9/1)(2/5) = 18/5 = 3 3/5 cups
To find how long it will take to fill the tank, you can use the idea that every 30 seconds will get you one gallon closer to being full.
This means to fill 50 gallons, you will need 50 groups of 30 seconds.
50 x 30 = 1500 seconds
1500/60 = 25 minutes.
It will take 25 minutes.
You could also think of it as filling 2 gallons every minute. It would take 25 of these.