Trinity

How many different triads can be selected from group 38 students?

Correct answer:

x =  8436

Step-by-step explanation:

$$\begin{gathered} C_3(38)=\left({\displaystyle \genfrac{}{}{0px}{}{38}{3}}\right)={\displaystyle \frac{38!}{3!(38-3)!}}={\displaystyle \frac{38\cdot 37\cdot 36}{3\cdot 2\cdot 1}}=8436 \\ x=\left(\genfrac{}{}{0px}{}{38}{3}\right)=8436 \end{gathered}$$

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