Question

Acylinder with base radius 7cm and height 28cm is placed on the ground. Another cylinder with same base radius and height 14cm is placed on top of it. The entire structure is to be painted except the bottom surface and the top surface of the lower cylinder at the cost of Rs.5 per cm2. Find the total cost of painting.Draw a diagram in support of your answer and colour the lateral surface area of the lower cylinder and upper cylinder with two different colours.

Answer 1

Answer:

Rs. 9240

Step-by-step explanation:

First we will find the L/S/A of cylinder 1

L/S/A of cylinder 1 =

$2\pi \times r \times h$

$2\times \frac{22}{7} \times 7cm \times 28cm$

$2 \times 22 \times 28$

$1232cm {}^{2}$

Now we will find the L\S\A of cylinder 2

L\S\A of cylinder 2=

$2\pi \times r \times h$

$2 \times \frac{22}{7 } \times 7cm \times 14cm$

$2 \times 22 \times 14$

$616 {cm}^{2}$

now we will add the two L/S/A as they are on top of each other.

L/S/A of both cylinder together = 1232cm^2 +616cm^2

= 1848cm^2

cost of panting 1 cm^2 = Rs. 5

cost of painting 1848 cm^2 = Rs.(1848 x 5)

= Rs.9240