Question

Can someone do these 2 questions with explanation quickly?

Answer 1

Answer:

height = 1m ; total cost for plastering is 708 rupees

Step-by-step explanation:

⇒ curved surface area of right circular cylinder is 2πrh

where r = base radius

h = height

given that curved surface area of right circular cylinder 4.4 $m^{2}$

radius is r = 0.7 m

=>  4.4 $m^{2}$ =  2π(0.7) h $m^{2}$

=>  h = (4.4) / (1.4π) m => h = 1m

⇒ length = 4.5 m , breadth = 3m , height = 5m of a room.

area of ceiling = (length)(breadth) = (4.5m)(3m) = 13.5 $m^2$

area of walls = 2(height)[ length + breadth ] = 2(5m)(4.5m + 3m) = 75$m^2$

total area of room = area of ceiling + area of walls = (13.5 + 75)$m^2$= 88.5$m^2$

cost of plastering at the rate of 8 rupees / $m^2$ is (88.5)(8) = 708 rupees