Q3 of 68 Page 15

The outer circumference of a circular race-track is 525m. The track is everywhere 14m wide. Calculate the cost of leveling the track at the rate of 50paise per square meter

Given,


Circumference of outer circle = 525m


Let radius of outer circle = R2m


Let radius of inner circle = R1m


So,


R2-R1 = 14 (equation 1)


= 2πR2 = 525



Put value of R1 in equation first


= 83.52 – R1 = 14


= - R1 = 14 – 83.52


= R1 = 69.52m


Area of path =





Cost of leveling the path = 6733.76×.50 = Rs 3388


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