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Question
A photograph of Billiard/Snooker table has dimensions as `1/10`th of its actual size as shown in the following figure:
The portion excluding six holes each of diameter 0.5 cm needs to be polished at rate of ₹ 200 per m2. Find the cost of polishing.
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Solution
Actual length = 25 × 10 = 250 cm
Actual breadth = 10 × 10 = 100 cm
Area of table = 250 × 100 = 25000 cm2
Radius of 1 hole = `0.5/2` = 0.25 cm
Area of 6 holes = 6 × πr2 = `6 xx 22/7 xx 0.25 xx 0.25` = 1.18 cm2
Area of portion excluding holes = 25000 – 1.18 = 24998.8 cm2
∴ Cost of polishing = ₹ `24999/10000 xx 200` = ₹ 500 (approx.)
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