On average it takes a particular gem cutter 75 minutes to map the cutting of 5 gems find how long it takes her to map the cutting of 25 gems

Every weekday, mr. jones bikes from his home to his job. sometimes he rides along two roads, the long route that is shown by the solid lines. other times, he takes the shortcut shown by the dashed line. how many fewer kilometers does mr. jones bike when he takes the shortcut instead of the long route?