Mathematics for IGCSE & O level - Number (Section 3 - No. 4)
If two lighthouses flash every 22 and 16 seconds, at what time will they flash together again if they flashed at 10 pm?
10:02:40
10:03:00
10:04:48
10:05:12
Spiegazione
176 seconds, the LCM, which converts to 2 minutes and 56 seconds. 10:00:00 + 00:02:56 = 10:02:56