Question

A room is two times longer than its breadth and it contains 360 m' of air. If the cost
of plastering its floor at Rs 40 per sq. metre is Rs 2,880, find the cost of plastering
its walls at Rs 45 per sq. metre.​

Answer 1

Answer:

8100

Step-by-step explanation:

l=2b

Volume of Room = lbh=2b*b*h=360

b^2h=180

Area of Floor = 2880/40=72 sq. m.

lb=72

lbh=360

72*h=360

h=360/72=5

b^2h=180

b^2*5=180

b^2=180/5=36

b=6

l=12

Area of walls =2h(l+b)=2*5*18=180

cost=180*45=8100