Question

S
12. The height of a room is 1/5 of the sum of its
length and breadth. Cost of preparing its wall
at the rate 4 per m2 is 640. What is the height
of the room?
(a) 4 m (b) 5 m
(c) 6 m (d) 7 m​

Answer 1

Answer:

SteArea of the four walls =(Rs.400÷  

2

1

​  

)

=800m  

2

.

Now b=  

4

1

​  

(l+b) or 2b

=(l+b)

∴ Area of 4 walls 2b(l+b)

⇒8b  

2

=800

∴b=10p-by-step explanation:

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