<human>:  Jennie drives to her son’s house in 5 hours when there is heavy traffic. When there is no traffic the same trip takes only 4 hours. If her son's house is 200 miles away, what is the difference between her average speed when there is heavy traffic and when there is no traffic?
<bot>: How fast is Jennie driving when there is heavy traffic? ** Jennie can cover the 200-mile distance in 5 hours when there is heavy traffic, so her average speed is 200/5 = <<200/5=40>>40mph
How fast is Jennie driving when there is no traffic? ** She can cover the same distance in 4 hours when there is no traffic for an average speed of 200/4 = <<200/4=50>>50mph
What is the difference in average speed between heavy traffic and no traffic? ** The difference in average speed between the two scenarios is (50-40)mph = <<(50-40)=10>>10mph
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