Question

The length,breadth and height of room are in the ratio 5:3:1 and the room contains 960m^3 of air. What is the cost of plastering its walls,floor and ceiling at Rs 30 per m^2 ?

Answer 1

let l,b,h be x
5x 3x 1x

volume of room = l * b * h
960 = 5x*3x*1x
960=15x
x=64m

lenght = 5x=5*64=320m
breadth=3x=3*64=192m
height=1x=1*64=64

cost = Rs 380640

Answer 2

Here is your answer....☺☺

The length,breadth and height of room are in the ratio 5:3:1.

Let the length , breath and height be 5x,3x and x respectively.

Volume of room = air contains by room

L×B×H = 960 m³

(5x)×(3x)×(x) = 960 m³

15x³ = 960 m³

x³ = 64 m³

=> x = 4m

Therefore,

Length = 5×4m = 20m

Breath = 3×4m = 12m

Height = 4m

Cost of plastering = TSA × 30 Rs./m²

= 2(LB+BH+HL) × 30

= 2(20×12+12×4+4×20) × 30

= 2(240+48+80)×30

= 2(368)×30

= 22080 Rs.

☺☺