In order to get miles per hour, we need to see how many miles she would swim in an hour. Because we know that she swims 1/2 of a mile in 2/5 of an hour, she would swim 1/4 of a mile in 1/5 of an hour. So, we multiply 1/4 by 5 to get 5/4th of a mile in 1 hour. Now we convert it to a mixed number, which is 1 1/4th miles per hour
