I NEED HELP WITH THIS MATH

Determine whether the following statements are true and give an explanation or counterexample. bold a. when using the shell method, the axis of the cylindrical shells is parallel to the axis of revolution. bold b. if a region is revolved about the y-axis, then the shell method must be used. bold c. if a region is revolved about the x-axis, then in principle it is possible to use the disk/washer method and integrate with respect to x or the shell method and integrate with respect to y.

You have 138.72 in your saving account u take out 45.23 and 18.00 you deposit 75.85 into your account

Askateboard ramp is in the shape of a right triangle what is the height of the ramp