Question

the length and breadth of a rectangular Garden are in the ratio 7 :3. If the area of the field is 525 square m, then find the cost of fencing is at rs.75 per m

Answer 1

Given the length and breadth of a rectangular garden is 7:3.

Let the length be 7x.    --- (1)

Let the breadth be 3x.  --- (2)

Given Area of the field = 525 sq.m

We know that Area = l * b

                           525  =  7x * 3x

                            525 = 21x^2

                            525/21 = x^2

                             25 = x^2

                              x = 5m.


Substitute x = 5 in (1) and (2), we get

Length = 7 * 5 = 35m .

Breadth = 3 * 5 = 15m.


We know that perimeter of the field = 2(l+b)

                                                            = 2(35 + 15)
 
                                                            = 100m.


Given the rate of fencing = 75 per meter.

The cost of fencing = 75 * 100

                                 = 7500m.



Hope this helps!

Answer 2

let x be the required no and

let 7x be the length n 3x be the breadth

A/Q
Area of rectangular field

=> lb = 525

=> 21x^2 = 525

=> x^2 = 25

=> x = 5 m
Hence length , => 7 × 5 => 35

breadth , => 3×5 = 15

Cost = rate × perimeter

= 75 × 100 ( by perimeter)

= ₹7500

Hence the cost is ₹ 7500
hope this helps u