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

NCERT Math Class 6th Question – 11 Exercise 3.7

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?

Solution:

(a) To find the LCM of 5 and 20, we have

∴ LCM = 2 x 2 x 5 = 20.
Hence, the LCM of 5 and 20 = 20.

(b) To find the LCM of 6 and 18, we have

∴ LCM = 2 x 3 x 3 = 18.
Hence, the LCM of 6 and 18 = 18.

(c) To find the LCM of 12 and 48, we have

LCM = 2 x 2 x 2 x 2 x 3 = 48.
Hence, the LCM of 12 and 48 = 48.

(d) To find the LCM of 9 and 45, we have

∴ LCM = 3 x 3 x 5 = 45.
Hence, the LCM of 9 and 45 = 45.
From the above examples, we observe that the LCM of the two numbers, where one number is a factor of the other, is the greater number.