Donald usually runs the same distance daily for a total of 28 miles per week, training for a marathon. This week he was unable to run for 3 days. How many miles was Donald able to run?

This size running track is usually called a 400 meter track. however if a person ran as close to the inside as possible on the track they would run less than 400 meters in one lap. how far away from the inside border would someone have to run to make one lap equal exactly 400 meters