Question

The length and breadth of the rectangle park are in the ratio 5 : 4 and its area is 2880 <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> $m^2$, find the cost of fencing the park at the rate of ₹5 per metre.

• A. ₹1000
• B. ₹1050
• C. ₹1080
• D. ₹2000

Answer 1

The correct option is C ₹1080

Let the length and breadth of the rectangle as per the given ratio be 5x and 4x.

We know, area of rectangle = length x breadth
So, the area of the rectangular park
= 5 <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> $x$ x 4 <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> $x$ = 20 <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> $x^2$

According to the question,
Area of the rectangular park is 2880 <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> $m^2$
So, 20 <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> $x^2$ = 2880
<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> $x^2$ = 144
<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> $x$ = 12
So, 5 <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> $x$ = 5 × 12 = 60
4 <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> $x$ = 4 × 12 = 48

So, the perimeter of the park
= 2 (length + breadth)
= 2 (60 + 48)
= 2 × 108
= 216 cm

For 1 m, the cost of fencing = ₹5
For 216 m, the cost of fencing
= ₹5 x 216
= ₹1080