The greatest common divisor of the three numbers is
[tex]GCD(60,48,42)=6[/tex]
This means that we can divide all numbers by 6:
[tex]60\div 6=10,\quad 48\div 6=8,\quad 42\div 6=7[/tex]
So, if each group has 10 nickles, 8 dimes and 7 quarters, you will form 6 groups.