Question

A classroom is 10m long,7m wide and 5m high . find the cost of plastering the wall at the rate of Rs 1.50 per m^2​

Answer 1

Given :-

• Length of the classroom = 10 m

• Breadth of the classroom = 7 m

• Height of the classroom = 5 m

To Find :-

• Cost of plastering the wall.

Solution :-

Cost of plastering the wall is at the rate of Rs 1.50 per m²

Total Surface Area :-

$:\implies\:\:\sf{2(lb+lh+bh)}$

$:\implies\:\:\sf{2(10 \times 7 +10\times 5 +7 \times 5)}$

$:\implies\:\:\sf{2(70 +50 +35)}$

$:\implies\:\:\sf{2\times155}$

$\orange{:\implies}\:\:\orange\sf{310\:m^2}$

∴ Total Surface area of the classroom = 310 m²

Area of the floor :-

⇒   l × b

⇒   10 × 7

⇒   70 m²

Area of the wall for plastering :-

⇒   310 - 70

⇒  240 m²

Cost for plastering wall :-

For 1 m²,

→   Rs 1.50

For 240 m²,

→  1.50 × 240

→  360

∴ Cost of plastering wall = Rs 360.