Maths
posted by Aravind on .
The radius of a wheel is 7 cm. In covering 44 km, how many revolutions will it make?

N = 44,000 m/(2*pi*0.07 m)
= 100,000 (rounded to 4 sig. figures) 
C = pi * d
C = 3.14 * 14
C = 43.96 cm = 0.4396 meters
1 km = 1000 m
Take it from there. 
circumference = 2 * pi * r
= 2 * 22/7 * 7
= 44 cm
1 km = 1,00,000 cm
44 km = 44,00,000 cm
revolutions to be made =
44,00,000/44
= 1,00,000 
C = 2 * pi * r
= 2 * 22/7 * 7
= 44 cm
1 km = 1,00,000 cm
44 km = 44,00,000 cm
revolutions to be made =
44,00,000/44
= 1,00,000