Thread: Questions part 1

1) A truck going 70 mph passes a parked highway patrol car. When the truck is half a mile past the patrol car, the officer starts going 100 mph. How long does it take the patrol car to overtake the truck?

2) Janelle can paint her fence in 3 hrs. Her friend Ryan estimates it would take him 4 hrs to paint the same fence. If they work together, how long will it take them to paint Janelle's fence?

3) With one hose a swimming pool can be filled in 10 hrs. Another hose can fill it in 12 hrs. How long will it take to fill the pool using both hoses?

Originally Posted by gobbluth

1) A truck going 70 mph passes a parked highway patrol car. When the truck is half a mile past the patrol car, the officer starts going 100 mph. How long does it take the patrol car to overtake the truck?

What is the difference in their rates? In other words, how fast would the car have to go to catch up at the same rate, were the truck to stop dead in its tracks once it was half a mile ahead?

What distance does the car have to "make up" on the truck?

How long will it take, at that relative speed, for the car to cover that distance?

Originally Posted by gobbluth

2) Janelle can paint her fence in 3 hrs. Her friend Ryan estimates it would take him 4 hrs to paint the same fence. If they work together, how long will it take them to paint Janelle's fence?

This one works just like the other "work" exercise you posted in another of your threads. Follow the method explained there.

Originally Posted by gobbluth

3) With one hose a swimming pool can be filled in 10 hrs. Another hose can fill it in 12 hrs. How long will it take to fill the pool using both hoses?

This is another "work" problem. If you get stuck working this or the previous one, please reply showing how far you have gotten.

Have fun!