The largest 4 digit number is 9999.We know that , if LCM of given numbers divide a number N , then N is exactly divisible by all the given numbers .LCM of 12,15,18,27 is 540.On dividing 9999 by 540 we get 279 as remainder.Therefore number =9999 - 279 =9720.
L.C.M. of 60 and 62 seconds is 1860 seconds1860/60 = 31 minutesThey will beep together at 10:31 a.m.Sometimes questions on red lights blinking comes in exam, which can be solved in the same way
L.C.M. of 2, 4, 6, 8, 10, 12 is 120. So, the bells will toll together after every 120 seconds(2 minutes). In 30 minutes, they will toll together 30 + 1 = 16 times. 2
L.C.M. of 5,6,7,8 = 840. Required number is of the form 840k + 3 Least value of k for which (840k + 3) is divisible by 9 is k = 2. Required number = (840 X 2 + 3)=1683
EXAMIANS