You can transform gallons into liters and you have that $1 g a l l o n = 3.785 l i t e r s$ so in 1 gallon (that costs 1.299 $) you have 3.785 liters. You now divide the price (of 1 gallon) by the number of liters you have in 1 gallon and you get the price per liter: $\frac{1.299}{3.785}/liters$= 0.343$ $/liter. The swimmer swims 85.4 yards=78.1 meters in 5 minutes that are (1 minute = 60 seconds) $5 \cdot 60 = 300$seconds; so he swims $\frac{78.1}{300} = 0.26$meters in 1 second; in 70 seconds he'll swim: $0.26 \cdot 70 = 18.22\$m.