To solve this, we need to first find out how many kilometers he rode for both Monday and Wednesday. To do this, add 13.94 and 18.23 together. The answer is 32.17 kilometers. Since we know he has to ride 50 kilometers for the week, we can subtract 32.17 from 50 to find the answer. Note that I didn't attempt to convert 32.17 to kilometers since that was the unit of measure it was already in. Now, after you have done 50-32.17, you will get 17.83. Put this in kilometers. This gives us our answer, which is 17.83 km. Mark needs to ride for 17.83 more kilometers to complete his training for the week.
When you convert from meters to centimeters, you always multiply by 100, which means that 1 meter = 1 * 100 cm = 100 cm So, 8.6 meters = 8.6 * 100 cm = 860 cm
