1. The rate of a small aircraft in calm air is 125 mph. If the wind is currently blowing south at a rate of 15 mph, how far north can a pilot fly the plane and return it within 3 h?
in miles... mi?
2. A new machine makes 10,000 aluminum cans three times faster than an older machine. With both machines operating, it takes 9 h to make 10,000 cans. How long would it take the new machine, working alone, to make 10,000 cans?
h=?
3. A twin-engine plane flies 400 mi in the same amount of time it takes a single-engine plane to fly 240 mi. The rate of the twin-engine plane is 80 mph faster than the rate of the single-engine plane. Find the rate of the single-engine plane.
mph=?
4.A plane can fly 160 mph in calm air. Flying with the wind, the plane can fly 516 mi in the same amount of time it takes to fly 444 mi against the wind. Find the rate of the wind.
mph=?
5. If it takes a janitorial crew 5 h to clean a company's offices, then in x hours the crew has completed of the job. ?
6. A manufacturer of prefabricated homes has the company's employees work in teams. Team 1 can erect the Silvercrest model in 30 h. Team 2 can erect the same model in 20 h. How long would it take for Team 1 and Team 2, working together, to erect the Silvercrest model home?
h=?
7. A backpacker hiking into a wilderness area walked 9 mi at a constant rate and then reduced this rate by 1 mph. Another 4 mi was hiked at this reduced rate. The time required to hike the 4 mi was 1 h less than the time required to walk the 9 mi. Find the rate at which the hiker walked the first 9 mi.
mph=?
8. After sailing 12 mi, a sailor changed direction and increased the boat's speed by 2 mph. An additional 16 mi was sailed at the increased speed. The total sailing time was 4 h. Find the rate of the boat for the first 12 mi.
mph=?
9. Working together, Pat and Chris can reseal a driveway in 6 h. Working alone, Pat can reseal the driveway in 9 h. How long would it take Chris, working alone, to reseal the driveway?
h=?
10. One technician can wire a security alarm in 8 h, whereas it takes 6 h for a second technician to do the same job. After working alone for 4 h, the first technician quits. How long will it take the second technician to complete the wiring?
h=?
11. A cement mason can construct a retaining wall in 12 h. A second mason requires 10 h to do the same job. After working alone for 6 h, the first mason quits. How long will it take the second mason to complete the wall?
h=?
12. An engineer traveled 180 mi by car and then an additional 615 mi by plane. The rate of the plane was three times the rate of the car. The total trip took 7 h. Find the rate of the car.
mph=?
13. The president of a company traveled 1800 mi by jet and 200 mi on a prop plane. The rate of the jet was four times the rate of the prop plane. The entire trip took 5 h. Find the rate of the jet.
mph=?