write 1/6, 2/6, 3/6, 4/6, 5/6, in the simplest form. why is 3/6 the only one of the sixths that terminates?

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?