Question: Tobias rode his bike on a road for a 2 hr period. On average, he passed a 1 km marker every 3 min during this period. Which of the following was his average speed for this 2 hr period?

  Options: 
 A. 10 km/hr
 B. 15 km/hr
 C. 20 km/hr
 D. 25 km/hr 
Answer: C