Answer:
5 hours
Step-by-step explanation:
This is a classic pre-algebra question.

124 sq in...................
GP = 1/2 , 1/4 , 1/8 , 1/16
1st) the common ratio is (1/4 : 1/2 ) = 1/2, so r =1/2
2nd) the sum of a GP is:
S= a(1-rⁿ)/(1-r)
S=(1/2).[1-(1/2)⁴]/(1-1/2) = 15/16
Hello.
It takes 3 4/5 bags of sand to fill in one sandbox.
Hope it helps you :)
Answer:
V = pi * R^2 * h
R = (V / (pi * h))^1/2 = (141.3 / (3.14 * 5))^1/2 = 3 cm