question_answer 56)

Find the LCM of the following numbers in which one number is the factor of the other. (a) 5, 20                                (b) 6, 18                                (c) 12, 48                              (d) 9,45 What do you observe in the results obtained?

Answer:

                (a) LCM of 5 and 20 2 5, 20 2 5, 10 5 5, 5 1, 1 \[\therefore \]LCM\[=2\times 2\times 5=20\] (b) LCM of 6 and 18 2 6, 18 3 3, 9 3 1, 3 1, 1 \[\therefore \]LCM\[=2\times 3\times 3=18\] (c) LCM of 12 and 48 2 12, 48 2 6, 24 2 3, 12 2 3, 6 3 3, 3 1, 1 \[\therefore \]LCM\[=2\times 2\times 2\times 2\times 3=48\] (d) LCM of 9 and 45 3 9, 45 3 3, 15 5 1, 5 1, 1 \[\therefore \] LCM\[=3\times 3\times 5=45\] Here, we observe that in all parts, LCM of the given numbers is the larger of two numbers because one number is the factor of the other number.