+612 When Helen jogs, every minutes she checks the total distance she traversed. One day, the first time she checked, Helen had jogged a distance of miles, the second time she checked, she had jogged a total distance of miles, and the third and final time that she checked, Helen found out that she jogged a total distance of miles. What is the difference between her average speeds, in miles per hour, during the first minutes of jogging and the last minutes of jogging?
