NCERT Solutions
Class 6 Maths
Playing with Numbers

Ex. 5.7 Q.10
Find the L.C.M. of the following numbers:
(a) 9 and 4 (b) 12 and 5 (c) 6 and 5 (d) 15 and 4
Observe a common property in the obtained L.C.Ms. Is L.C.M. the product of two numbers in each case?
(a) Factor of 9 = 3 * 3
Factor of 4 = 2 * 2
LCM(9, 4) = 2 * 2 * 3 * 3 = 36
Now, product of two numbers = 9 * 4 = 36
So, L.C.M. is the product of two numbers.
(b) Factor of 12 = 2 * 2 * 3
Factor of 5 = 1 * 5
LCM(12, 5) = 2 * 2 * 3 * 5 = 60
Now, product of two numbers = 12 * 5 = 60
So, L.C.M. is the product of two numbers.
(c) Factor of 6 = 2 * 3
Factor of 5 = 1 * 5
LCM(6, 5) = 2 * 3 * 5 = 30
Now, product of two numbers = 6 * 5 = 30
So, L.C.M. is the product of two numbers.
(d) Factor of 15 = 3 * 5
Factor of 4 = 2 * 2
LCM(15, 4) = 2 * 2 * 3 * 5 = 60
Now, product of two numbers = 15 * 4 = 60
So, L.C.M. is the product of two numbers.
Again, L.C.M. is the multiple of 3 in each case.