Question

The cost of levelling a rectangular field at
50 per square metre is 30,000. If its length
and breadth are in the ratio of 3:2, then find
its perimeter.​

Answer 1

Answer:

this is the answer of your question

Answer 2

The perimeter of the given rectangular field is 100 units.

• Let l be the length and b be the breadth of the rectangular field.

• Given,

Length : Breadth = 3:2

Or, length (l) = 3y, breadth (b) = 2y

Therefore, area of the field = l × b = 3y × 2y = 6y²

• Cost of levelling the field = Rs. 50 / m²

=> Total cost of levelling the field = area × cost per m²

=> Total cost = 6y² × Rs. 50

Also given, total cost of levelling the field = Rs. 30,000

• According to the question,

6y² × Rs. 50 = Rs. 30,000

Or, y² = Rs. 30,000 / (Rs. 50 × 6)

Or, y² = 100

Or, y = +10, -10

Since area cannot be negative, the value -10 gets discarded.

• Therefore, length of the field (l) = 3y = 3 × 10 = 30 units

Breadth of the field (b) = 2y = 2 × 10 = 20 units

• Perimeter of the rectangular field = 2 (l + b) = 2 (30 + 20) units

=> Perimeter of the field = 2 × 50 units

=> Perimeter of the field = 100 units