Fred's painting rate 1 house per 12 hours plus George's rate of 1 house per 14 hours gives their combined rate as 1/12 + 1/14 = 7/84+6/84 = 13/84ths of a house per hour. Let this equal to 1 house per x hours, so 1/x = 13/84 Taking reciprocals of both side x = 84/13 = 6 6/13 hours. Edwin