A red light flashes every 14 minutes. A blue light flashes every 24 minutes. When will the two light flash together again, if they last flashed together at 8:00 am?
The LCM of 14 and 24 is 168. So 168 minutes after 8 a.m. the lights will flash again. 168 minutes is 2 hours and 48 minutes. Add that to 8 a.m. and you get 10:48 a.m. which is your answer.