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.

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:)))))

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.

a) To calculate the surface area of the block that Peter will paint black, we need to find the area of the circular base of the cylinder and the lateral surface area of the cylinder.

The formula for the area of a circle is A = πr^2, where r is the radius. The diameter given is 6 cm, so the radius is half of that, which is 3 cm.

Area of the circular base = π(3 cm)^2 = 9π cm^2.

The formula for the lateral surface area of a cylinder is A = 2πrh, where r is the radius and h is the height.

Lateral surface area = 2π(3 cm)(18 cm) = 108π cm^2.

So, the total surface area to be painted black is the sum of the circular base area and the lateral surface area:

Total black surface area = 9π cm^2 + 108π cm^2 = 117π cm^2.

b) To calculate the surface area of the block that Peter will paint white, we need to subtract the black surface area from the total surface area of the block.

The formula for the total surface area of a cylinder is A = 2πr(r + h).

Total surface area = 2π(3 cm)(3 cm + 18 cm) = 2π(3 cm)(21 cm) = 126π cm^2.

Total white surface area = Total surface area - Total black surface area:

Total white surface area = 126π cm^2 - 117π cm^2 = 9π cm^2.

c) The cost C of painting the block can be expressed in terms of the black surface area (b) and the white surface area (w) as follows:

C = (cost of black paint per unit area) * b + (cost of white paint per unit area) * w.

Since black paint costs $0.03 for every 12 cm^2 painted and white paint costs $0.04 for every 15 cm^2 painted, we can substitute these values into the equation:

C = ($0.03/12 cm^2) * b + ($0.04/15 cm^2) * w.

d) To calculate the value of C for Peter's block, you would need the specific values of b and w. However, you have not provided these values, so it is not possible to calculate the exact value of C.

e) To determine whether or not Lorenzo could paint his entire block white for less than or equal to $1.00, we need to calculate the cost of painting the entire block white.

If the total white surface area is 9π cm^2 (as calculated in part b), then we can substitute this value into the equation from part c:

C = ($0.04/15 cm^2) * 9π cm^2.

Simplifying the equation, we have:

C = $0.04/15 * 9π = $0.024π.

So, Lorenzo could paint his entire block white for less than or equal to $1.00 if $0.024π is less than or equal to $1.00.