HCF=Highest Common Factor-HCF of two or more numbers is the greatest factor that divides the numbers. For example, 2 is the HCF of 4 and 6.
LCM=Least Common Multiple-LCM is the smallest positive number that is a multiple of two or more numbers.
Answers:
1) 6
2) 12
3) 5
4) 3
5) 26
6) 15
7) 88