Here you will find solved problems on LCM & GCM by "Factorisation" method.
Find LCM & GCM.
Formula For GCM= All the common factors in all numbers.
LCM= GCM x All Uncommon Factors(Note: When uncommon factors occur twice or more
times then take this uncommon factor once.)
"Factorisation" method
1) 15,20,35
Factors 15=5 x 3
20=2 x 2 x 5
35=5 x 7
GCM=5.......(Common factor in all numbers)
LCM=GCM X Uncommon Factors
=5 X 3 X 2 X 2 X 7
=420
2) 12,30,10
Factors 12=2 x 2 x 3
30=2 x 3 x 5
10=2 x 5
GCM=2.......(Common factor in all numbers)
LCM=GCM x Uncommon Factors
= 2 X 2 X 3 X 5......(Note: Here 3 & 5 appeared twice, so we took them once.)
=60
Examples for pracice:
Find out LCM & GCM of following by factorization method.
1) 15,25,35.
2) 40,55,60.
3) 12,15,18.
4) 21,35,27.
5) 16,40,24.
Find out LCM & GCM of following by division method.
1) 22,24,30.
2) 18,15,24.
3) 13,15,7.
4) 60,80,100.
5) 2,3,11.
