From the question,
The cost of fence = ₹ 24 per mater
The total cost of fencing a rectangular piece of land = ₹ 9600
Let the length of the rectangular field = 5x
The breadth of the rectangular field = 3x
Then,
perimeter of the rectangular land = 2 ( l + b )
= 2 (5x + 3x)
= 2 (8x)
= 16x
Perimeter of the given field = (total cost of fencing / Rate of fencing)
16x = (9600/24)m
16x = 400m
x = 400/16
x = 25
∴ the length of the rectangular field = 5x = 5 × 25 = 125m
The breadth of the rectangular field = 3x = 3 × 25 = 75m