math
posted by mikey .
i have a 36 in. wide by 18 in. length by 20 in high rectangular aquarium that needs to be filled. i have a 12 in high cylindrical bucket with a 12 in diameter to fill the tank. if the aquarium contains 3 in of gravel and the bucket is to be filled to a depth of 11 in, how many buckets of water will it take to fill the aquarium?

Assuming the aquarium is to be filled to the top, 20" high less 3" of gravel,
volume of water V1 = 36*18*17 in^3.
Capacity of each bucket filled to 11" high
V2=π(6)^2*11=396π in^3
Number of buckets required = V1/V2
round to the next higher integer.
I get 9 buckets.