Petr has a cylindrical block of wood od diameter 6 cm and height 18 cm. He glues the base to a board, but wants to paint the rest of the block. He wants to paint the bottom half of the wood black and the top half white.

Question

a) Calculate the surface area of the block that Peter will paint black.
b) Calculate the surface area of the block that Peter will paint white.

The black paint will cost Petr $0.03 for every 12 cm^2 painted and the white paint will cost ether $0.04 for every 15 cm^2 painted.

c) If b represent the area of the black surface and w represents the white surface, write an expressionf for the cost C of painting the block in terms of b and w.

d) Calculate the value of C for Peter's block.

e) Determine whether or not Lorenzo could paint his entire block white for less than or ezual to $1.00.

Please could you help me check my answer please, please??

a) black:
area of circle C= 18.849 cm
area of rectange 9x18.849 = 170 cm^2

b) white:
169.641 + 28.274 = 198 cm^2

The rest I don't know:((
Thank you so much for everything:)))))

Answer 1

value of block is:
169,641 x0.03 $ / 12 = 0.42 $
197.901 X 0.04 $/ 15 = 0.527736 $

0.42 + 0.527736 = 0.947736 $
Petr could paint his entire block less than to $1.oo.