Question

A hotel installs dual-flush toilets to help conserve water. The new toilets use 1.6 gallons for one full flush and 0.9 gallons for one partial flush. Measurements show that in the first week there were 1,190 full flushes and 3,150 partial flushes. How many gallons of water were saved for the week compared to a week in which all the flushes were full flushes?

Answer 1

If all the flushes were full flushes: 1190 + 3150 = 4340 full flushes in total. Because the full flush uses 1.6 gallons, multiply 4340 and you get 6944 gallons of water used per week before the partial flushes were installed.

(1190 full flushes * 1.6 gallons) + (3150 partial flushes * 0.9 gallons) = 4739 gallons used.

Subtract 4739 gallons from 6944 gallons to get the amount of gallons saved for the week, which is 2205 gallons.