Question

3. The cost of fencing a rectangular field
at Rs.20 per meter is Rs.2600. If the
breadth of the field is 10m, then find its
length​

Answer 1

Given :-

• Cost of fencing a rectangular field per meter = Rs. 20

• Total cost of fencing = Rs. 2600

• Breadth of the rectangle = 10 m

To Find :-

• Total length of fence = 2600/20 = 260/2 = 130 m

Formula used -

• Perimeter of rectangle.

Solution -

In the question, we are provided with the Breadth of rectangle, total cost and rate, and we need to find the length, as it it given, total cost of fencing, that means, we have to use the formula of perimeter of rectangle, from that we will obtain our length. Let's do it!

So -

Let the length be termed as l

According to question -

Perimeter of rectangle = 2(L + B)

Where,

P = Perimeter = 130m

L = Length = l

B = Breadth = 10m

On substituting the values -

130 = 2(l + 10m)

130 = 2l + 20m

2l = 130 - 20m

2l = 110

l = $\sf\cancel\dfrac{110}{2}$

l = 55 m

$\therefore$ The length of the rectangle is 55 m.

Verification -

Perimeter = 2(l + b)

130m = 2(55m + 10m)

130m = 2(65m)

130m = 130m

Rate give = ₹20 per m

Total cost = ₹20 × 130m

Total cost = ₹2600

Hence verified

_______________________________________________________

Answer 2

Answer:

Given :-

• Cost of fencing = ₹2600
• Cost of fencing 1 m = ₹20
• Breadth = 10 m

To Find :-

Length

Solution :-

Firstly lets find perimeter of Field

$\sf \pink {Perimeter = \dfrac{total \: cost}{cost \: of \: fencing \: 1 \: m}}$

$\sf \: Perimeter = \dfrac{2600 }{20}$

$\sf \: Perimeter = 130 \: m$

Let the length be l

As we know that

$\bf \: Perimeter = 2(l + b)$

$\sf \: 130 = 2(l + 10)$

$\sf \: 130 = 2l + 20$

$\sf \: 130 - 20 = 2l$

$\sf \: 110 = 2l$

$\sf \: l = \cancel \dfrac{110}{2}$

$\frak \red{l = 55 \: m}$