



 
Hi Rachel. Assuming they have a normal fourtired vehicle, they have a total of 4 x 18,000 = 72,000 miles of wear to put on some tires. If each tire is good for 12,000 miles, then they need 72,000 / 12,000 = 6 tires in total, but they need to plan carefully to make sure they rotate them at the right time, or they'll be stuck! Here's one of many ways they could do it using tires A. B. C. D. E. F:
Cheers, PS: With the price of gas these days, I'd be more concerned about the fuel price of this trip than the tires! :)  


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