Question

A swimming pool is 20 m in length, 15 m in breadth, and 4 m in depth. Find the cost of cementing its floor and walls at the rate of Rs 12 per square metre​

Answer 1

Given:

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• Length of the swimming pool is 20 m
• Breadth of the swimming pool is 15 m
• Depth of the swimming pool is 4 m

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To find:

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Cost of cementing its floor and walls at the rate of Rs 12 per square metre.

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Solution:

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We know that,

Lateral surface area of cuboid = 2h(l + b)

$\therefore$ Area of the four walls of the swimming pool = 2h(l + b)

= {2 × 4 × (20 + 15)} m$^{2}$

= 8 × 35 m$^{2}$

= 280 m$^{2}$

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Area of the floor of the swimming pool

= l × b

= 20 × 15 m$^{2}$

= 300 m$^{2}$

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$\therefore$ Total area to be covered = Area of the four walls of the swimming pool + Area of the floor of the swimming pool

= 280 + 300

= 580 m$^{2}$

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Cost of cementing of 1 square metre = Rs 12 (given)

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$\therefore$ Cost of cementing the floor and the walls = (12 × 580) = Rs 6869