SAT Math Multiple Choice Practice Question 218: Answer and Explanation
20. A wheel with a diameter of 24 inches rolls along the ground. If it rotates 150 times, approximately how far will the wheel travel, in feet?
Correct Answer: C
C. Each time the wheel rolls, it travels the length of its circumference. Remember that circumference = 2πr or πd. So, in this case, the circumference is 24π inches, or 2π feet. Multiply that distance by 150 rotations, and the distance is 2π(150) = 300π.