Problems on H.C.F and L.C.M
The traffic light at three different road crossing change after every 48 sec, 72 sec. and 108 sec. respectively . If they all change simultaneously at 8 : 20 : 00 hours, then at what time will they ag
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