SPEED         TIME        DISTANCE
 
Pablo          5r         15/(5r)         15

Jose            r         15/r            15

Difference                 2

Let r be the Jose's rate bicycling, in miles per hour.

Then, according to the condition, the Pablo's rate driving is 5r miles per hour (five times as fast).



Jose's time bicycling 15 miles  is    hours.

Pablo's time driving 15 miles  is   =   hours.



The difference of times is 2 hours, giving you equation

     -  = 2  hours.



Simplify and find "r" 


     = 2;

    r =  = 6 miles per hour.


ANSWER.  Jose rides his bicycle at  6 miles per hour.