Question

the length and breath of a rectangular piece of land are in the ratio 5:3. if the total cost of fencing at rupees 7per meter is rupees 2800,find the area of the plot

Answer 1

perimeter of rectangle =2800 /7
let l be 5x and b be 3x then
2(l+b)=400
2×(5x+3x)=400
16x=400
x= 400/16
x=25
so l = 5 × 25 = 125
b = 3×25 =75

Answer 2

L= 5x
B= 3x
perimeter = l +b
=2( 5x + 3x)
= 16x
perimeter × rate = total cost
perimeter ×7. = 2800
perimeter=2800/7
perimeter= 400
now perimeter = 2*( l+b)
400. = 16x
400/16. =x
thus, x=25
hence l= 5*25
=125 units
b=3*25
=75 units
400/15=x^2