A school'd academic team consists of 6 students, but only 3 of them can participate. How many different 3 person teams can be formed from the 6 students?

Question

anonymous · Answer

Have you learned C$$C _{b}^{a}$$

anonymous · Answer

no

anonymous · Answer

OK I will think another way to tell you

anonymous · Answer

let make it easier 
four boys and two of them participate
how many ways

anonymous · Answer

2?

anonymous · Answer

your have four choices when you choose the first boy, right?

anonymous · Answer

I mean you have to choose one boy first and four is the number of your choice

anonymous · Answer

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anonymous · Answer

your choice can be 12 13 14 23 24 34

anonymous · Answer

21 31 41 32 42 43 is also your choices 
because the first and the second is not the same

anonymous · Answer

ok i get it thanks