Question

please do solve this it is from mensuration chapter
ans is 11,813.50 but i need solution ​

Answer 1

Answer:

The correct answer is Rs. 11,812.50

Step-by-step explanation:

Length = Twice breadth & Thrice Length

Cost of carpeting the floor = Rs. 9000

Rate of carpeting the floor = Rs. 80/m²

So, Area of floor = $\frac{9000}{80} m^{2}$ = $\frac{225}{2} m^{2}$

Let the breadth be x

Therefore, Length = 2x

$x(2x) = \frac{225}{2}$

$=> 2x^{2} = \frac{225}{2}$

$=>x^{2} =\frac{\frac{225}{2} }{2}$

$=> x^{2} = \frac{225}{4}$

$=> x = \sqrt{\frac{225}{4} }$

$=> x = \frac{15}{2}$

Therefore, Breadth = 15/2 m

Thus Length = 15/2 X 2 = 15 m

So, Height = 15/3 m = 5 m

There are 4 walls so area of them = [2 ( 15 X 5 ) + 2 (5 X 15/2)] m² = [2 X 75 + 2 X 75/2] m² = [150 + 75] m² =225 m²

Area of floor = Area of ceiling = 225/2 m² = 112.5 m²

Therefore total plastering are = (225 + 112.5) m² = 337.5 m²

Rate of Plastering = Rs. 35/m²

So, total cost of plastering = Rs. 35 X 337.5 = Rs. 11,812.50

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