Can somebody please clarify the difference between these two questions? I know how to do them but I don't fully understand why you must divide the # of ways the groups can be moved around in the first question but not the second.
1. In how many ways could a class of 18 students divide into groups of 3 students each? (Answer is 190590400)
2. How many ways could 15 different books be divided equally among 3 people? (Answer is 756756)
For question 2, I arrived at 756756 by doing (15C5) x (10C5) x (5C5). Then I proceeded to divide the product by 3! because I thought I had to cancel out the ways the 3 groups repeated in arrangements. What am I doing wrong?
1. In how many ways could a class of 18 students divide into groups of 3 students each? (Answer is 190590400)
2. How many ways could 15 different books be divided equally among 3 people? (Answer is 756756)
For question 2, I arrived at 756756 by doing (15C5) x (10C5) x (5C5). Then I proceeded to divide the product by 3! because I thought I had to cancel out the ways the 3 groups repeated in arrangements. What am I doing wrong?