No Lunch Break?
A contractor's dredge can travel 7 miles per hour. It attempts to move up a river where the current downstream is 1 3/4 miles per hour. After 2 hours, engine trouble develops. The dredge drifts with the current for an hour and a half while the engine is being repaired. After repairs are completed the boat proceeds at its former speed to its destination 27 miles up the river from the starting point. How long did the whole trip take (including time lost for repairs)?
Source: W.C. Eddy's Wartime Refresher in Fundamental Mathematics, 1945, p. 17-18