Question

During a running and kayaking race, Oscar plans to run each mile in 7 minutes and kayak each mile in 22 minutes. At this pace, he will finish the race in 101 minutes. If he runs each mile in 8 minutes and kayaks each mile in 20 minutes, he will finish the same race in 100 minutes. In the equations below, r represents the number of miles run, and k represents the number of miles kayaked.


7r + 22k = 101
8r + 20k = 100

How many miles will Oscar run during the race?