Question

length of classroom is two times its height and its bredth is one and a half times its height .the cost of white washing the walls at the rate of rs.1.60 per m2 . is Rs 179.20 . find the cost of tiling the floor at the rate of RS.12.75 PER M 2.

Answer 1

sorry.

h





and is it 672.6m

Answer 2

Answer:

Rs.612

Step-by-step explanation:

Let the height be h

We are given that length of classroom is two times its height

So, Length = 2h

we are also given that  its breadth is one and a half times its height .

So, Breadth = $1\frac{1}{2}h=\frac{3h}{2}$

Area of white washing for cost Rs.1.60 = 1 sq.m.

Area of white washing for cost Rs.1 = $\frac{1}{1.6}$ sq.m.

Area of white washing for cost Rs 179.20  = $\frac{1}{1.6} \times 179.20$ sq.m.

                                                                     = $112$ sq.m.

So, lateral surface area of classroom = 112 sq.m.

Lateral surface area of cuboid $= 2(l+b)h$

So, Lateral surface area of classroom  $= 2(2h+\frac{3h}{2})h$

So,  $112= 2(2h+\frac{3h}{2})h$

$112= (4h+3h)h$

$112= 7h^2$

$16= h^2$

$4=h$

So, length = 2h = $2 \times 4 = 8 m$

Breadth = $\frac{3h}{2} =\frac{3\times 4}{2} = 6$

Area of floor = $Length \times Breadth$

                     = $8\times 6$

                     = $48 m^2$

Cost of tiling 1 sq.m. = Rs.12.75

Cost of tiling 48 sq.m. = $12.75 \times 48$

                                     = $612$

Hence  the cost of tiling the floor is Rs.612