Math
Mira has 20 gallons of water. She used 8 1/2 gallon to water the roses and 7 1/2 gallons to water lilies. How much water does she use have left?
asked by
Carolyn

20  (8 1/2 + 7 1/2) = _________ gallons
posted by Ms. Sue

how many half gallons?
started with 40 which is 2*20
first used 17 which is 2*8 +1
then used 15 which is 2*7 +1
so
40  17  15 = 8 half gallons
which is 4 whole gallons.
posted by Damon
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