Thu 10 Feb, 2011 09:45 pm
Ali and his bloodhound Crawford are chasing Preston. Preston has a 10 mile head start but Ali is walking 1 mph faster than Preston. Crawford is trained to run to Preston, run back to Ali and then continue running back and forth between them. If Crawford runs 10 mph, how far does he run before Ali finally catches up to Preston?
Pursuant to your question:
Ali is faster by 1mph so he will catch up with Preston in 10 hours.
In the interim the dog has run for 10 hours at 10 mph.