My finals are tomorrow and i need to sleep soon, any answer would be appreciated, and i REALLY REALLY need explanations with the answer

To find the answer for question 7 we would first need to find the volume of the cylinder as a whole.  To find a cylinders volume all you need to do is input values into this formula V=πr2h.  In our case the volume is 508.94.  Now we would need to subtract out the volume of the cone that was carved out.  To find the volume of a cone use this formula, V=πr2h /3.  The volume of the cone is 113.1.  Now subtract 113.1 from 508.94 to get 395.84 which rounds to 396 in cubed.  This means that B) is your answer.  Now for question #11.  This is quite similar to the other problem but this time it involves adding a cone and cylinders volume together instead of subtracting them.  Follow the same steps as before except add instead of subtract.  The volume of this cylinder is 1017.88.  The volume of the cone on top is 37.7.  Add these two values together to get 1055.58 which is your answer.  As for the last one which is question #4 which asks us to solve for the angle all we would need to do is find out what x is equal to and then input that into the equation given for angle Q and solve!  To solve for x follow these steps.  (11x -5)+(6x+5)+(x)=180  Set the equations for each angle equal to 180 as that is the sum of all angles in all triangles.  Then solve for x.  We get that x = 10.  Now plug in x = 10 into the equation for angle Q. 11(10)-5=105.  This means that angle Q is 105 degrees.

i believe the answer is the polygon, heptagon.