Question

A tent is in the form of a cylinder of diameter 4.2 m and height 4 m, is surmounted by a cone of equal base and height 2.8 m. Find the cost of canvas required for making the tent at ₹100 per sq.m.

• A. ₹ 6590
• B. ₹ 7590
• C. ₹ 8590
• D. ₹ 9876

Answer 1

The correct option is B

₹ 7590

The total surface area of the tent:

$T=2\pi r{h}_1+\pi rl\pi =\frac{22}{7};r=2.1\text{m}{h}_1=\text{height of the cylinder}=4\text{m}{h}_2=\text{height of the cone}=2.8\text{m}l=\text{slant height of the cone}l=\sqrt{{2.8}^2+{2.1}^2}=3.5\text{m}$

So,

$T=(2\times \frac{22}{7}\times 2.1\times 4+\frac{22}{7}\times 2.1\times 3.5)T=75.9{\text{m}}^2$

Therefore, the total cost of canvas at ₹100 per sq meter = $75.9\times 100=₹7590$.