It takes 1 and 3/4 hours to fill a new underground gasoline storage tank. What part of the tank would be fill if the gasoline had been shut off after 1 hour?
Proportions:
100% : 1.75 hours
x% : 1 hour
x=1*100%/1.75
100% : 1.75 hours
x% : 1 hour
x=1*100%/1.75