JAMB - Mathematics (2014 - No. 38)
In how many ways can a team of 3 girls be selected from 7 girls?
\(\frac{7!}{3!}\)
\(\frac{7!}{4!}\)
\(\frac{7!}{3!4!}\)
\(\frac{7!}{2!5!}\)
Giải thích
A team of 2 girls can be selected from 7 girls in \(^7C_3\)
\( = \frac{7!}{(7 - 3)! 3!}\)
\( = \frac{7!}{4! 3!} ways\)
\( = \frac{7!}{(7 - 3)! 3!}\)
\( = \frac{7!}{4! 3!} ways\)