If water flows into a rectangular tank at the rate of 6 cubic feet per minute, how long will
it take to fill the tank, which measures 18''x 32'' x 27''

The volume of a rectuangular prism is length×width×height

in this case, the volume will be 18×32×27 = 15,552 cubic inches.

water flows in by cubic feet, so we'll need to either transformthe volume of the tank to feet, or the volume of water flow to inches. in this case, it will make our life easier if we turn the tank valume into feet. 15,552 inches is exactly 1296 feet. 

water flows in 6 cubic feet per minute, so we calculate that 1,296 ÷ 6 = 216

water will be flowing in for 3 hours and 36 minutes thusly.