WAEC - Further Mathematics (2015 - No. 15)
In how many ways can a committee of 5 be selected from 8 students if 2 particular students are to be included?
20
28
54
58
解释
Since 2 students must be included, we have to arrange the remaining 3 students from the 6 students left
= \(^{6}C_{3} = \frac{6!}{(6-3)!3!}\)
= 20 ways