In how many ways can 2 students be selected from a group of 5 students in a debating competition?
- 25 ways
-
10 ways
- 15 ways
- 20 ways
The correct answer is: B
Explanation
\(In\hspace{1mm} ^{5}C_{2}\hspace{1mm}ways\hspace{1mm}=\frac{5!}{(5-2)!2!}\\=\frac{5!}{3!2!}\\=\frac{5\times4\times3!}{3!\times2\times1}\\=10\hspace{1mm}ways\)