If 3feet*50metre is Rs.8720,how much would 2feet*40metre cost?

3ft*50m/(2ft*40m) = Rs. 8720/ Rs. x

x = 80(8720)/150 = 4650 2/3 or 13952/3 or appr. 4650.67
(the units canceled)

To find the cost of 2 feet * 40 meters, we can use the information given in the question and the concept of proportionality.

First, let's calculate the cost per unit area:
3 feet * 50 meters = Rs. 8720
The area in square meters is (3 feet * 0.3048 meters/foot) * 50 meters = 45.72 square meters.
So, the cost per square meter is Rs. 8720 / 45.72 square meters = Rs. 190.51 per square meter.

Next, we can find the area of 2 feet * 40 meters:
The area in square meters is (2 feet * 0.3048 meters/foot) * 40 meters = 24.384 square meters.

Finally, we can calculate the cost of 2 feet * 40 meters:
The cost is (area in square meters) * (cost per square meter) = 24.384 square meters * Rs. 190.51 per square meter = Rs. 4647.96.

Therefore, the cost of 2 feet * 40 meters is Rs. 4647.96.