A certain road goes up one side of a hill and back down the other side. Each of the two segments is one mile long. If I drive my car up the hill at a constant speed of 30 mph, how fast must I drive the downhill segment to average 60 mph for the entire trip?
Hint: If you did this in your head, you're probably wrong.
Hint: If you did this in your head, you're probably wrong.