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 5, 6, 7, 8 = 840.Required number is of the form 840k + 3Least value of k for which (840k + 3) is divisible by 9 is k = 2.Required number = (840 x 2 + 3) = 1683.
The number students in each room = HCF of 70,98 and 126 =14 In each room , maximum 14 students can be seated. Total number students = 70 + 98 +126 =294 Number of rooms required = 294/14 =21