Question

A door is 2.6 m by 1.1 m.find the cost of painting both sides of the door at the rate of rs 20 per square metre

Answer 1

Given that the measurements of door are 2.6 m and 1.1 m

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Area of rectangle = length x breadth

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Area of rectangle = 2.6 m x 1.1 m

Area of rectangle = 2.86 m^2

Area of door from both sides = 2 x 2.86 m^2

Area of door from both sides = 5.72 m^2

In the question it is given that  the cost of painting both sides of the door at the rate of rs 20 per square metre.

Here, area of the region which is to be painted is 5.72 m^2

∴ Cost of painting both sides of the door at the rate of Rs 20 per m^2 = Rs  20 m^2 x 5.72 m^2

Cost of painting both sides of the door at the rate of Rs 20 per m^2 = Rs 114.4

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Answer 2

$\mathbb{ SOLUTION }$

length and breadth of door = 2.6m × 1.1m

Area of the door = 2.9 × 1.1 = 2.86 m²

According to the question,
The door has to be painted both sides.

So area of door from both sides
= 2 × 2.89 = 5.72 m²

Now,
if the cost of painting the door pee m² = Rs 20

So the total cost to paint the door both sides
= 20 × 5.72 = Rs. 114.4