My question is: Jill can run up a hill at 9 feet/second and down a hill at 12 feet/second. How long does it take her to run up and down a 900 foot hill? Your thoughts:
First find the time it takes Jill to run up the hill: 900 feet / 9 feet / second = 100 seconds. Then find the time it takes Jill to run down the hill: 900 feet / 12 feet / second = 75 seconds. Then add the two times to find Jill's total time: 100 seconds + 75 seconds = 175 seconds. The final answer: 175.