Shoveling 1/5 of the driveway = 2/5 hours
Shoveling the entire driveway (5/5) would take 2/5 (the time it takes to shovel 1/5) times/multiplied by 5 (5/5 is the entire driveway)
2x5 is 10, so it would take 10/5 hours, which can be reduced to 2/1 or 2 hours to shovel the entire driveway.