Question

The ratio between the sides of a room is 4:5. The cost of white washing the ceiling of the room at 50 P per square m is Rs. 270 and the cost of papering the wall at 10 P per sq. m is Rs. 48 . The height of the room is ?
A) 8m
B) 5 m
C) 12 m
D) 10 m
E) None of these​

Answer 1

Answer:

Correct option is 5m

Step-by-step explanation:

Area of the ceiling

=

Costof1sq.unit

Totalcost

=

0.50.

Rs.270

=540

l:b=5:3 or l=5x and b=3x

so that, 5x×3x=540m

2

⇒x

2

=36m

2

or x=6m

∴ l=30m; b=18m

Area of the four walls

=

Costof1sq.unit

Totalcost

∴Height=

2(l+b)

Areaoffourwalls

=

2(30+18)

480

=5m