Each friend would get 8 rocks
42- Total number of rocks
5- Number of people that have to get the same # of rocks (frank included)
so you would do 42 ÷ 5 = 8.4
However, you can't give each person 8.4 rocks, so you would just give each person 8 rocks. When you do this each person will have the same amount
Yes, you will have 2 rocks left out, but thats okay