This is Giancoli Answers with Mr. Dychko. In order to compare miles with meters, we'll have to convert this mile into meters and there are 1610 meters per mile and so the miles cancel here and we are left with, well, that. To find the percent difference between these two race distances, we'll take the difference in the distances so that's 1610 meters for the regular mile minus the metric mile of 1500 meters and then divide by 1500 meters and the reason I know that we are dividing by 1500 meters and not dividing by 1610 meters is because we are told how much longer is such and such than such and such than a 1500 meter race. So the thing that comes second in that statement, how much longer is a 1-mile race than a 1500-meter race this the thing that's mentioned second— the 1500-meters—is what goes on the bottom here. So the regular mile is 7.3 percent longer than the metric mile.
I think the answer they are looking for is 7.3% longer.
My fault. I read your answer wrong.
Actually, I defer to your original observation, that the answer should be expressed as the percentage by which the one mile race is longer. The video is correct, but I've updated the Quick Answer.