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?
Step-by-step reasoning:
30
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.

.

Final answer: 30