Question 934670
circumference = 2*pi*r = 2*pi*40 centimeters = 80 * pi centimeters = 251.3274123 centimeters


1 km = 1000 meters.
1 meter = 100 centimeters.
1 km = 1000 * 100 = 100,000 centimeters.
10 km = 10 * 100,000 = 1,000,000 centimeters.


1,000,000 centimeters divided by 251.3274123 centimeters for each revolution of the bicycle wheel  = 3978.873577 revolutions of the bicycle wheel.


each revolution of the wheel is 251.3274123 centimeters long.
251.3274123 * 3978.873577 revolutions equals a total distance of 1,000,000 centimeters.
1,000,000 centimeters equals 10 kilometers.