Question

the cost of whitewashing of four walls of the room comes to rs. 10. what will be the cost of whitewashing a room of exactly twice the Length breadth and height of the room​

Answer 1

2 h [l+b] =rs.10

if h=2 h

l=2 l

b=2 b

so, 2[2 h]{2 l+ 2 b}

    4 h*2{l+b}

     8 h{l+b}

      4[2 h{l+b}]

and 2 h{l+b} =10

so,   4{10}=40

hence 40 Rs. will be the answer