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A table cover of dimensions 3 m 25 cm × 2 m 30 cm is spread on a table. If 30 cm of the table cover is hanging all around the table, find the area of the table cover which is hanging - Mathematics

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Question

A table cover of dimensions 3 m 25 cm × 2 m 30 cm is spread on a table. If 30 cm of the table cover is hanging all around the table, find the area of the table cover which is hanging outside the top of the table. Also find the cost of polishing the table top at ₹ 16 per square metre.

Sum
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Solution

To find the cost of polishing the table top, we have to find its area for which we require its length and breadth.

Given, length of cover = 3 m 25 cm = 3.25 m and breadth of cover = 2 m 30 cm = 2.30 m

∴ Area of the table cover = 3.25 × 2.30 = 7.475 m2

Since, 30 cm width of cloth is outside the table an each side.

∴ Length of the table = 3.25 – 2 × 0.30 = 2.65 m ...`[∵ 1  cm = 1/100 m]`

And breadth of the table = 2.30 – 2 × 0.30 = 1.70 m

∴ Area of the top of the table = (2.65 × 1.70) m2

= 4.505 m2

Area of the hanging table cover = Area of table cover – Area of the top of the table

= (7.475 – 4.505) m2

= 2.97 m2


It is given that, the cost of polishing the table top is at the rate of ₹ 16 per square metre.

Therefore, cost of polishing the top = Area × Rate per square metre

= 4.505 × 16

= ₹ 7.208

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Chapter 9: Perimeter and Area - Exercise [Page 290]

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NCERT Exemplar Mathematics [English] Class 7
Chapter 9 Perimeter and Area
Exercise | Q 104. | Page 290

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