<em>we need to know the TOTAL average speed. To do that, we need to know how to get the speed, which is distance/time. Now we have to substitute. The equation we get is: s= (90+120)/(1.5+3). After solving, you should get s= (210miles)/(4.5hrs). Now all we have to do is divide, which equals 46.6666667.</em>
You would convert 500 inches to centimeters, which is 500 times 2.54= 1270, then divide that by 365 days, leaving you with an answer of 3.47945205479, or just 3.47 centimeters.
