Gemma recently rode her bicycle to visit her friend who lives 12 miles away. On her way there, her average speed was 5 miles per hour faster than on her way home. If Gemma spent a total of 2 hours bicycling, find the two rates.

A man can drive a motorboat 64 miles down the Colorado River in the same amount of time that he can drive 16 miles upstream. Find the speed of the current if the speed of the boat is 10 mph in still water.

Antonio and Jeremy work for a plumbing company that was recently awarded a contract to install the plumbing fixtures in a new office complex. There are 12 bathrooms in the building. It takes Jeremy 4 hr longer than Antonio to complete one bathroom. If they work together it takes 8 hr to compete a bathroom. Find the rate at which each individual can complete a bathroom working alone.

A trucker drove 175 miles to make a delivery and returned home on the same route. Because of foggy conditions, his average speed on the return trip was 10 mph less than his average speed going. If the return trip took 2 hours longer, how fast did he drive in each direction? going ? mph returning ? mph