Question

Find the LCM of the following numbers in which one number is the factor of the other
1. 5, 20
2. 6, 18
3. 12, 48
4. 9, 45
What do you observe in the results obtained?

Answer 1

(a) L.C.M. of 5 and 20
= 2 x 2 x 5
= 20

---

(b) L.C.M. of 6 and 18
= 2 x 3 x 3
= 18

---

(c) L.C.M. of 12 and 48
= 2 x 2 x 2 x 2 x 3
= 48

---

(d) L.C.M. of 9 and 45
= 3 x 3 x 5
= 45
From these all cases, we can conclude that if the smallest number if the factor of largest number, then the L.C.M. of these two numbers is equal to that of larger number.