Metal sheet required to make a hollow and closed cylindrical box of diameter 20 cm and height 35 cm. Given that the width of the metal sheet is 1 m. Also, find the cost of the sheet at the rate of Rs. 56 per m. Find the area of metal sheet required, if 10% of it is wasted in cutting, overlapping, etc.

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18 cm and Rs.15.68; 3111cm2

28 cm and Rs.15.68; 3111cm2

38 cm and Rs.15.68; 3111cm2

48 cm and Rs.15.68; 3111cm2

answer is B.

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Detailed Solution

Given, a hollow and close cylinder of diameter 20 cm and height 35 cm. The width of the sheet is 1m and the cost of the sheet is Rs. 56/m.
Radius = 5 cm
So, we have to find total surface area.
Total surface area =2πr (r + h)
=

2 × 227 × 10 × (10 + 35)

= 2828.57 cm2 = 0.282 m2
Cost of sheet = 0.282 × 56 = Rs.15.8
Length of sheet = width of sheet / Area of sheet = 0.282/1 = 0.28 m = 28 cm
Area of metal sheet if 10% is wasted then sheet required = Area of sheet + 10% of sheet
=2828.57 + 10% of 2828.57
=2828.37 + 282.8
=3111.57cm2
Length of sheet, Cost of sheet and Area of metal sheet if 10% is wasted are 28 cm and Rs.15.68; 3111cm2
Hence, Option (2) is the correct answer.

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