With box and whisker plot, the first quartile is where the box starts. In this case it’s 6. The median of this set is 8, represented by the line inside the box. The third quartile is where the box ends, 11 in this case.
The whiskers show the lowest and highest numbers of the data set.
Sean drove at a faster rate because if you divide each miles/minutes then it gives you how many miles per minute they drive. 20/5 is 4, and 45/9 is 5, and 5 is greater than 4.