Question: James injured his ankle and decides to slowly start working back up to his previous running goals and then surpass them. Before the injury, he was able to run 100 miles per week. He wants to get up to 20% more than that total in 280 days and each week he will increase miles walked in the week by the same amount. How many miles does he need to add per week? Think carefully first, then make a decision:
He wants to run 100 * .2 = 20 miles more than he used to. So he needs to run 100 + 20 = 120 miles. He is doing this in 280 / 7 = 40 weeks. So he needs to add 120 / 40 = 3 miles per week. So the answer is 3.