Four machine makes a beep after every 15, 30, 40 and 45 minute respectively. In 30hrs, how many times do they beep together if they have just beeped together?
LCM of 15, 30, 40 and45 = 360 That me ans: after 360 minute they will beep again together. 1360 minute = `360/60` hrs = 6hrs Then number of beep in 30hrs = `30/6` = 5 times
