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Question

The Sharks at the zoo requires the 117 gallon tank to be 7​% salt. After a period of​ time, some water​ evaporated, raising the salinity to

9​%. How many gallons of water must be resupplied in order to bring the salinity back down to

7​%?

Answer 1

.07(117) = .09(117-x)

.09(117)-.07(117) = .09x

.02(117) = .09x

x = .02(117)/.09 = .02(13)/.01 = 2(13) = 26

26 gallons of water are need to restore salinity to 7%