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
Required length = H.C.F. of 495 cm, 900 cm and 1665 cm. 495 = 3² x 5 x 11, 900 = 2² x 3² x 5², 1665 = 3² x 5 x 37. H.C.F. = 32 x 5 = 45. Hence, required length = 45 cm.