If you run 3 miles everyday for 5 days, how many miles will you need to run on the sixth day in order to have run an average of 4 miles per day over 6 days? Solve this problem in two different ways, and explain your solutions.

Answer 1

6 * 4 = 24 miles
3 * 5 = 15 miles

24 - 15 = 9 miles on day 6