Can someone check these and tell me the middle one

Acylinder and its dimensions are shown. which equation can be used to find v, the volume of the cylinder in cubic centimeters?

If your teacher tells you to do questions 6 through 19 in your math book for homework, how many questions is that

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?