A race track is in the form of a ring whose inner and outer circumfere

1.	A race track is in the form of a ring whose inner and outer circumferences are 440 m and 528 mrespectively. Find the width of the track and also its area
Answer» Let radius of inner ring is r1radius of outer ring r2 Now,Circumference of inner ring= 2pir12pir1 = 440222/7r1 = 440r1 = 107 = 70 Circumference of outer ring= 2pir22pir2 = 528222/7r2 = 528r^2 = 127 = 84 Width of track = 84-70 = 14 m Area of track = pir2r2 - pir1r1= 22/7(8484 - 7070)= 22(1284 - 1070)= 22(1008 - 700)= 22(308)= 6776 m^2

A race track is in the form of a ring whose inner and outer circumferences are 440 m and 528 mrespectively. Find the width of the track and also its area

Answer»

Let radius of inner ring is r1radius of outer ring r2

Now,Circumference of inner ring= 2pi*r12pi*r1 = 4402*22/7*r1 = 440r1 = 10*7 = 70

Circumference of outer ring= 2pi*r22pi*r2 = 5282*22/7*r2 = 528r^2 = 12*7 = 84

Width of track = 84-70 = 14 m

Area of track = pi*r2*r2 - pi*r1*r1= 22/7(84*84 - 70*70)= 22(12*84 - 10*70)= 22(1008 - 700)= 22(308)= 6776 m^2