#### Answer

c

#### Work Step by Step

a. 15 + 5 = 20, which is not 28 gallons.
b. 20 gallons is not 3 times as much as 8 gallons (8x3=24)
c. 21 gallons is 3 times as much as 7 gallons (7 x 3 = 21) and 21+7=28 total gallons

Published by
Pearson

ISBN 10:
0321726391

ISBN 13:
978-0-32172-639-1

c

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