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An environmental organization has 19 members. Each member will be placed on exactly 1 of 4 teams.
Each team will work on a different issue. The first team has 3 members, the second has 5, the third has 7, and the fourth has 4.
In how many ways can these teams be formed?
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1. You can select 3 members from 19 members to the 1-st team by ways.
2. Then you can select 5 members from remaining 19-3 = 16 members to the 2-nd team by ways.
3. Then you can select 7 members from remaining 16-5 = 11 members to the 3-rd team by ways.
4. Then you can select 4 members from remaining 11-7 = 4 members to the 4-th team by = 1 ways.
(Actually, you just have no choice at this last step).
5. In total, you have * * ways to form yours teams.
Thus I just explained the methodology to you, and I leave to you making the calculations.
Last notice: the quantities are the numbers of combinations of "n" things taken "k" at a time.
See the lesson Introduction to Combinations in this site.