If he took 3 breaks in 6 hours, that means he takes a break every 2 hours. If he traveled 36 hours taking a break every 2 hours. 36 ÷ 2 = 18 breaks of 10 minute each break. That would be 18 x 10 = 180 minutes or 3 hours of break time out of 36 hours of travel.
Hope this helps you out. :-)
