5 yards to 1 second (5:1)
There are 3600 seconds in 1 hour
X yards to 3600 seconds (x:3600)
5x3600=x--->18000 yards in 3600 seconds
18000 yards in one hour
There are 1760 yards in 1 mile
1760/1=18000/m---> 18000/1760= 10.2272727. Round: a little more than 10 miles per hour.
FINAL ANSWER: he can ride his bike about 10 miles per hour