Question

The surface of water pool is in the shape of a square whose side is 450 cm. Its exterior 20 cm width and the edge part is cemented along the side of the square. Find the area of that cemented part. Find cost for cementing if the rate is ₹ 15 per sq.cm.

Answer 1

Given inner side of the pool (s) = 450 cm 

Inner area of waterptool ABCD = s × s 

= 450 × 450 

= 202500 sq.cm Width of the edge = 20 cm

Here path is running outside the pool. 

So, outer side of the pool 

(s) = s + 2 × w 

= 450 + 2 × 20 

= 450 + 40 = 490 cm 

Outer area of water pool EFGH 

= s × s 

= 490 × 490 

= 2,40,100 sq.cm 

Area of the edge = Outer area – Inner area 

= 240100 – 202500

Area of the path = 37,600 sq.cm 

Cost of cementing per sq.cm = ₹ 15 

∴ Cost of cementing per 37600 sq.cm 

= 37,600 × 15 

= ₹ 5,64,000