Question

a room is of dimensions 7.3 m (length), 5.4 m (width) and 5 m (height). The ceiling and the four walls are colour washed at the rate of Rs 12 per m2. find the cost of colour washing. Also, the floor has to be carpeted at the rate of Rs 55 per sq. dm. find the cost of carpeting the floor.

Answer 1

area = TSA + roof area
= 2h(l+b) + lb
$= 2 \times 5(7.3 + 5.4) + 7.3 \times 5.4 \\ = 10(12.7) + 39.42 \\ = 127 + 39.42 \\ = 166.42 \: {cm}^{2} \\ cost = \: \frac{166.42}{10 \times 10} \times 55 \\ = 91.531 \: rs$
hope this helps..... correct me if I am wrong....

Answer 2

Area = area of four walls + area of roof

= 2h( L+b) + lb

= 2×5( 7.3 + 5.4 ) + 7.3 × 5.4

= 166.42 square m.

1.Cost of 1 square metre colour washing = Rs 12

Cost of 166.42 sq. m. Colour washing = Rs 12 × 166.42 = 1997.04 Rs

Area of flour = l×b

= 7.3×5.4 = 3942 square dm.

Cost of carpeting the room at the rate of Rs 55per squat dm = 3942 × 55Rs = 216810Rs.