The central hall of a school is 80m long and 8m high. It has 10 doors each of size 3m1.5m and 10 windows each of size
size 1.5m1m. If the cost of whitewashing the walls of of the hall at the rate of ₹1.20 per sq m is ₹2385.60, find the breadth of the hall.

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Solution

Area Of Walls = 2(l+b)h

Area = 2(80+b)8

Area = (160+2b)8

Area = 128+16b

Now Area To Be Whitewashed = Area Excluding Windows And Doors

Area Of Windows = 1.5110 = 15

Area Of Doors = 31.510 = 45

Area To Be Whitewashed = 128+16b - (45+15) = 16b+68

Cost = Rs 1.20 Per m2

Total Cost = (16b+68)1.20 = 19.2b+81.6

This Equals Rs 2385.60

19.2b+81.6 = 2385.60

19.2b = 2304

b = 120m

Hence Breadth Of Hall = 120 m

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The central hall of a school is 80m long and 8m high. It has 10 doors each of size 3m*1.5m and 10 windows each of size ​​size 1.5m*1m. If the cost of whitewashing the walls of of the hall at the rate of ₹1.20 per sq m is ₹2385.60, find the breadth of the hall.

The central hall of a school is 80m long and 8m high. It has 10 doors each of size 3m1.5m and 10 windows each of size
size 1.5m1m. If the cost of whitewashing the walls of of the hall at the rate of ₹1.20 per sq m is ₹2385.60, find the breadth of the hall.