A truck driver picked up a hitch-hiker as he traveled northwards out of the city. After some time, the hitch-hiker remarked that every 10 minutes they passed a truck going in the opposite direction. "How many trucks will arrive in the city in an hour" he asked, "assuming that the trucks are traveling at equal speeds in both directions?" The driver replied "Six, it is obvious because 60 diveded by 10 is 6." Was he Correct?
NO
If the Driver and the Hitch-hiker were stationary then he would be correct, but they are moving too. It takes them 10 minutes to meet a truck, but each time they pass one, it takes that truck a further 10 minutes to meet a truck. So the actuall time between trucks is 20 minutes not 10. In fact only 3 trucks arrive in the city every hour.