My question is: Mary's sheep can run 12 feet per second, and her sheepdog can run 20 feet per second. A sheep standing 160 feet away from the sheep dog bolts, and the dog runs after it. How many seconds does it take the dog to catch the sheep? Your thoughts:
User
First find how much faster the dog is than the sheep: 20 feet / second - 12 feet / second = 8 feet / second. Then divide the distance the dog needs to run by the speed difference: 160 feet / 8 feet / second = 20 seconds. The final answer: 20.
Assistant