Make the number of decimal places in all the given numbers the same i.e., 0.12, 0.15, 0.2 and 0.54LCM of 12, 15, 20 and 542|12 15 20 542|6 15 10 273|3 15 5 275|1 5 5 9 1 1 1 9LCM=22×3×5×9=540 LCM=540/10 =5.4
L.C.M. of 6, 9, 15 and 18 is 90.Let required number be 90k + 4, which is multiple of 7.Least value of k for which (90k + 4) is divisible by 7 is k = 4.Required number = (90 x 4) + 4 = 364.