Question 983642
Nancy's speed is x mph
Sam's is x+67 mph
Nancy traveled a total of 5 hours
Sam traveled 2 hours
distance is time* speed; distances are equal, since Nancy was caught.

5x=2(x+67)
5x=2x+134
3x=134
x=44 2/3 mph for Nancy; x+67=111 2/3 mph for Sam

Check
Sam left after Nancy had traveled 134 miles (44 2/3 times 3)
He was traveling at 67 mph faster than she.
Therefore, he caught her in 2 hours.