Answer:
a. 40000pi ft^3
b. 5 times
Step-by-step explanation:
a. the volume of a cylinder is pi * h * r^2
r = 20ft, h = 100ft
so V = pi * 100 * 20^2 = 40,000pi or around 125663.7 ft^3
b. to find the number of times, divide the volume by the amount of salt needed per storm then round down:
40000pi/21000 = 5.98 so 5 times. notes: depending on the teacher you might just round to the nearest integer