Question

The sides of a rectangular lawn are in the ratio of 5:3. If
the area of the lawn is 3375 m2, find the cost of fencing
the lawn at Rs. 8.50 per meter.
STEP BY STEP ​

Answer 1

Step-by-step explanation:

Cost of fencing lawn =RS65 per metre.

Area of lawn =3375m  

2

 

Length: Breadth =5:3

Length =5x

Breadth =3x

We know, Area of lawn =Length×Breadth

⇒3375=5x(3x)

⇒3375=15x  

2

 

⇒225=x  

2

 

or x=15m

Therefore,  

Length =5x=5×15=75m

Breadth =3x=3×15=45m

Now,  

Perimeter of lawn =2(length+breadth)

=2(75+45)

=2×120

=240

Perimeter is 240m

Cost of Fencing =240×Rs65 per meter =Rs15600.

Answer 2

Answer:

let the length of the rectangular lawn(l) = 5x

and breadth (b) = 3x

so,area of the lawn = l×b

3375. = 5x × 3x { given area]

3375 = 15x^

3375/15 = x^

√225 = x

15 = x

so, actually length of the lawn = 5x = 5×15 = 75m

and breadth = 3x = 3×15 = 45 m

the cost of fencing the lawn at Rs. 8.50 per meter.

= Rs. 8.50 × perimeter of the lawn

= 8.50 × 2(l+b)

= 8.50 × 2 (75+45)

= 17 × 120

= Rs. 2,040