Step 1
Write an expression for the equality between gallon and quartz

Step 2
Convert all necessary units in gallon to quartz and sum them up to find the water Christain had left
Leftovers include



Sum all together to find all water left

Therefore Christain has 11 3/4 quartz of water left.(Answer)
Step-by-step explanation
1 gallon = 4 quartz ( given standard)
5/2 gallon = X quartz
Cross multiply
1 gallon x X quartz = 5/2 gallon x 4 quartz
1 gallon x X quartz = 5/2 gallon x 4 quartz
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1gallon 1 gallon
X quartz = 10 quartz