If the cyclist traveled 2/3 of his journey already, then the remainder would be 1/3 of his journey, which we know is 30 miles. Double that and we have the miles he traveled during the first 2/3, 60. Then divide 60 by the miles per hour, 12, to get 5 hours. Add in the 3 hours from the remaining 1/3 of the journey and you have your total; the cyclist's trip took 8 hours.