Question

A swimming pool is 50cm in length, 30cm in breadth and 2.5cm in depth. Find the cost of cementing its floor and walls at the rate of rupee 27 per square metre.

Answer 1

Length= 50cm=0.5m
Breadth=30cm=0.3m
Depth=2.5cm=0.025m

As the swimming will be open from top,so only 5 sides will be cemented.

$area = 2(lb + bh + lh) - lh \\ = 2((0.5 \times 0.3) + (0.3 \times 0.025) + (0.5 \times 0.025)) - (0.5 \times 0.025) \\ = 2(0.15 + 0.006 + 0.012) - 0.012 \\ = 2(0.168) - 0.012 \\ = 0.336 - 0.012 \\ = 0.324 {m}^{2}$
Now,Rate of cementing the wall = Rs27/m²
Cost = Rs 27 × 0.324
= Rs 8.75

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