HELP PLS WITH PART A AND B OR ONLY A!! TY:)

Find the volume of the solid generated when the region bounded by y= x and y= 4√x is revolved about the x-axis the volume of the solid is: (type an exact answer cubic units)

Does the problem involve permutations or? combinations? do not solve. the matching section of an exam has 4 questions and 7 possible answers. in how many different ways can a student answer the 4 ? questions, if none of the answer choices can be? repeated?

How many solutions does the nonlinear system of equations graphed below have? a. one b. zero c. four d. two