You have to multiply to find it
If the probability of getting heads is 1/2 and you flipped a coin 200 times you would land on heads 100 times
Surface area of cylinder is given by area of circle + area of the rectangle that curved around the cylinder
Area of the base of the cylinder =

Area of the cylinder 'wall' = width × length =

×

=

×

=

Note that the wall of the cylinder is in the shape of a rectangle. The width of the rectangle is the height of the cylinder. The length of the rectangle is the circumference of the circle base.
Surface area of cone is given by

where

is the slanted height of the cone
SA of cone =

Hence total painted surface area is
2X^2+22x+318=1270
2x^2+22x-952=0
x^2+11x-476=0
(x+28)(x-17)=0
x=17