Question

The cost of fencing a circular plot at the rate of Rs.15 per m is Rs.3300. What will be the cost of flooring the plot at the rate of Rs.100 per sq m?

• A. Rs.385000
• B. Rs.220000
• C. Rs.350000
• D. Cannot be determined

Hint:

Find the radius from the fencing cost first, then use it to get the area.

Answer 1

The Correct Option is A

Step 1: Find the radius from the fencing cost.
The circumference of the circular plot is \(2\pi r\), and fencing it at Rs.15 per metre costs Rs.3300, so \(2\pi r \times 15 = 3300\), which gives \(2\pi r = 220\). Using \(\pi = \frac{22}{7}\), \(2 \times \frac{22}{7} \times r = 220\), so \(r = \frac{220 \times 7}{44} = 35\) m.

Step 2: Find the area and the flooring cost.
Area of the circular plot \(= \pi r^2 = \frac{22}{7} \times 35^2 = \frac{22}{7} \times 1225 = 3850\) sq m. Flooring at Rs.100 per sq m costs \(3850 \times 100 = 385000\).

Final Answer:
The cost of flooring the plot is Rs.3,85,000, so option D (cannot be determined) is wrong since the radius can in fact be found. \[ \boxed{Rs.\,3{,}85{,}000} \]