if the diameter of a bike wheel is 20cm, what's the minimum number of revolutions needed to cover 1km?

Answer 1

1km = 1000 m

100cm = 1 m

convert to meters and divide

Answer 2

Diameter d = 20 cm
Circumference C = pi * d
C = 3.14 * 20 = 62.8 cm in one revolution

62.8 cm
100 cm = 1m
62.8/100 = 0.628 m

0.628 m in one revolution
1 km = 1000 m
1000/0.628 = 1592.36 revolutions