A plane flies from Los Angeles west to Paradise Isle and returns. During both flights there is a steady upper air wind from the west at 80 mph. If the trip west to Paradise Isle took 17 hours and the return trip to Los Angeles took 13 hours, what was the plane's average airspeed?

I’m stuck on this equation, anyone got the answer?

For every corresponding pair of cross sections, the area of the cross section of a sphere with radius r is equal to the area of the cross section of a cylinder with radius and height 2r minus the volume of two cones, each with a radius and height of r. a cross section of the sphere is and a cross section of the cylinder minus the cones, taken parallel to the base of cylinder, is the volume of the cylinder with radius r and height 2r is and the volume of each cone with radius r and height r is 1/3 pie r^3. so the volume of the cylinder minus the two cones is therefore, the volume of the cylinder is 4/3pie r^3 by cavalieri's principle. (fill in options are: r/2- r- 2r- an annulus- a circle -1/3pier^3- 2/3pier^3- 4/3pier^3- 5/3pier^3- 2pier^3- 4pier^3)

The angle of elevation from point a to the top of the cliff is 38 degrees. if point a is 80 feet from the base of the cliff , how high is the cliff ?