Question

Find the LCM and HCF of the following integers by applying the prime factorisation method:

 84, 90 and 120

Answer 1

84, 90 and 120

Let us first find the factors of 84, 90 and 120

`84=2^2xx3xx7`

`90=2xx3^2xx5`

`120=2^3xx3xx5`

L.C.M of 84,90 and 120 =`2^3xx3^2xx5xx7`

L.C.M of 84,90 and 120 = 2520

H.C.F of 84,90 and 120 =6