Question

A cylindrical block of wood has a radius 70cm. And length 2cm.met is to painted with blue coloured enamel. The cost of painting it is Rs.1.25 per 100cm.^2. Find the cost of polishing the block.

Answer 1

Answer:

7920/100

Step-by-step explanation:

Total surface area = 2πr(r+L)

= 440*72

Cost = (1.25/100)*440*72

Answer 2

Correct question:

A cylindrical block of wood has a radius of 70cm. And length 2m.met is to paint with blue colored enamel. The cost of painting it is Rs.1.25 per 100cm.^2. Find the cost of polishing the block.

The cost of polishing the block is $Rs1485$.

Step-by-step explanation:

Given:

The radius of the cylindrical block of wood is $70cm$.

Length $h=200cm$.

The cost of painting it is $Rs.1.25$ per $100cm^{2}$.

To find:

To find the cost of polishing the block.

Formula used:

The total surface of the cylindrical block $=2\pi r(r+h)$.

Solution:

$=2\times\frac{22}{7} \times70\times(70+200)cm^{2}$

$=440\times 270cm^{2}$

$=118800cm^{2}$

The coat of paint $100cm^{2}$ is $Rs 1.25$ $=\frac{5}{4}$.

Then, the Cost of painting $118800cm^{2}$ is $Rs\frac{5}{4} \times118800$

$=Rs1485$

Hence, the cost of polishing the block is $Rs1485$.

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