Answer:

Step-by-step explanation:
The computation of the total amount of water needed could be determined by using the volume formula which is shown below:

where
L = length,
W = width,
and D = depth.
Now putting the values to the above formula
Therefore, the total amount of water needed is 
We simply applied the above formula
Answer:
1. 30 mins
Step-by-step explanation:
Answer is B, 21.6
Let me know if you need an explanation
Using the formula then calculator to get the ans and we must never forget to write the unit in squared form.