The sides of a rectangular park are in the ratio 4:3. If its area is 1728 m2, find the cost fencing it at Rs.30 per meter.
Length of the rectangular park=4x and Breadth of the rectangular park=3x
Area of the rectangular park=l×b
⇒1728=4x×3x
⇒12x2=1728
⇒x2=172812=144
⇒x=12 m
∴ sides of the rectangular park are
Length of the rectangular park=4x=4×12=48 m and
Breadth of the rectangular park=3x=3×12=36 m
∴ Perimeter of the land=2(l+b)=168m
Cost of fencing a land per meter=Rs.30
Cost of fencing a land of 168m=Rs.30×168=Rs.5,040