A person wishes to fence 375\text{ m}^{2} rectangular garden. He has 65\text{ m} of barbed wire and is able to fence <strong>ONLY</strong> three sides of the garden. What is the perimeter of the garden?

  1. A. 80\text{ m}
  2. B. 84\text{ m}
  3. C. 90\text{ m}
  4. D. 100\text{ m}

Correct Answer: A. 80\text{ m}

Explanation

Let dimensions be l, b. Area = lb = 375. Perimeter of 3 sides = l+2b = 65. We get l(65-2l) = 375 \implies 2l^2 - 65l + 375 = 0. Solving this gives l=25 or 7.5. If l=25, b=15. The total perimeter is 2(25+15) = 80\text{ m}.

Related questions on Mensuration

Practice more CDS Elementary Mathematics questions