GRE MATH QUESTION

Question

A manager is forming a 6 person team to work on a certain project. From the 11 candidates available the manager has already chosen 3. In selecting the other 3 how many different combinations of 3 of the remaining candidates does the manager have to choose from?

Answer 1

Hi Sowon,

Although the manager is forming a 6 person team, she already chose 3 of them so the problem reduces to choosing 3 persons from a pool of 8 (11 - 3). This can be done in 8 C 3 ways or 8!/(5!*3!) = 56.

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Sujith

Answer 2

Hi Sowon,

Since three people have already been chosen, then 8 are left. We are choosing 3 of them. The notation for this calculation is often written as 8C3, a function that many calculators can do. Or, if you are familiar with factorial notation (for example, 4! means 4*3*2*1), then the formula for 8C3 is 8! / (3! * 5!) which is equal to 56 combinations.

Please let me know if I can be more helpful, thanks!

Joe