I really need help on these types of problems...for ex, here is one from a practice test:

A company employs 6 senior officers and 4 junior officers. If a committee is to be created of 3 senior officers and 1 junior officer, how many different committees are possible?

The correct answer is 80. Can you please show me how to do this?

Thanks

Hello,
the way to select 3 senior engineers out of 6 without any repetition would be 6C3 and the formula is 6!/(3!x3!) which would give 20 ways. Then to selct 1 junior engineer out of 4 it would be 4C1 and again 4!/(1!x3!) gices us 4. total number of combinations would be 20x4=80.

Hope this helps. these type of problems are known as permutation combination problems and you can look more of these up on the wolfram math website for a better understanding.