we can use
volume of cone formula

where
r' is radius of cone
h' is height of cone
we are given
The radius of the cone is half the radius of the cylinder
so,

The height of the cone is equal to the radius of the cylinder
so,

now, we can plug values into formula
we get

we can simplify it

so, option-C.........Answer
Answer:
There is a 4% decrease
Step-by-Step:
if the previous total was 50, then each animal represents 2%. 50*2=100. if you are increasing the dogs by 20% of 20, then you are increasing them by 4 equaling out to 24 dogs. If your decreasing the cats by 20% of 30, then you are decreasing them by 6 equaling out to 24 cats. The new total of animals is now 48. Seeing how each animal still represent 2%, the new percentage is 96%. Subtracting the previous percentage from the new percentage gives a 4% difference.
50 * 2 = 100%
20 * 1.2 = 24
20 * .8 = 24
24 + 24 = 48
48 * 2 = 96%
100% - 96% = 4%
The coordinates of F' is (-9 + 3, 2 - 8) = (-6, -6)
answer to the question: b