3 1/2 miles in 30 minutes means that Susan can run 7 miles per hour
2 1/3 miles in 20 minutes means that Amber can run 7 miles per hour.
Because [tex]3 \frac{1}{2}\times 2 = \frac{7}{2} \times 2 = 7 [/tex]
[tex]2 \frac{1}{3}\times 3 = \frac{7}{3} \times 3 = 7 [/tex]
This means that both of them run at the same speed, and that no one is faster than the other. So, both girls are wrong.
