The five tires that come with Mary's new car were rotated frequently so that each tire was used for exactly the same amount of time as the others. They were replaced when the odometer read 24,000 miles. How many miles had each been driven?
It is stated that all tires are used for exactly same time. Current oddometer reading is 24000. Thus they must be rotated at equal intervals....
Thus the tires must be rotated at (24000/5) miles = 4800 miles.
These are the 5 equal intervals. Now car needs 4 tires at a given time to run. Thus all tires will be used for exactly 4 of those intervals.
Hence total miles on each tire = 4800 * 4 = 19200 miles....ANS