Problem of the Week - Middle School - Nov. 1, 2020 to Nov. 7, 2020

Middle School:

Question: Bobby is riding his tricycle around a quarter-mile track. If each wheel is 12 inches in diameter and turns 100 times, then how much further does Bobby need to pedal in order to complete a lap around the track? 

Answer: 1,006 feet

Solution: Each time the wheels rotate, Bobby moves forward 2πr ≈ ½ foot × 3.14 × 2 = 3.14 feet. Since a mile is 5,280 feet, the track is 5,280 ÷ 4 = 1,320 feet. If Bobby turns his wheels 100 times, he will travel 314 feet, which means he will have 1,320 – 314 = 1,006 feet left to complete a lap around the track.