



 
Hi Amanda, The distance between the two cars is decreasing. In 1.7 hours it decreases from 142 miles to 0 miles. What is the average speed at which it decreases in miles per hour? Suppose the speed of the slower car is s miles per hour then the speed of the faster car is 3s miles per hour. Thus the distance between the cars is decreasing at s + 3s = 4s miles per hour. Solve for s. Penny  


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