My question is: Rosie runs 6 miles per hour. She runs for 1 hour on Monday, 30 minutes on Tuesday, 1 hour on Wednesday, and 20 minutes on Thursday. If she wants to run 20 miles for the week, how many minutes should she run on Friday? Your thoughts:
On Monday and Wednesday, Rosie runs 6 * 1 = 6 miles. On Tuesday, Rosie runs 6 * (30 minutes / 60 minutes) = 3 miles. On Thursday, Rosie runs 6 * (20 minutes / 60 minutes) = 2 miles. So far this week Rosie has run 6 + 3 + 6 + 2 = 17 miles. To reach her goal, she must run 20 - 17 = 3 miles on Friday. Thus, she should run for 6 / 3 = .5 hour which is 30 minutes. The final answer: 30.