1. ## Combinatorics

Can I hv help on solving this?

a) In a mathematics class with 30 students, the teacher wants 2 different students to present the solutions to problems 3 & 5 on the board. In how many ways can the teacher assign the problems?

b) Find the number of ways in which a team of 6 bats-men, 4 bowlers and a wicket- keeper may be selected from a squad of 8 bats-men, 6 bowlers and 2 wicket-keepers.

Thnx

2. Originally Posted by cu4mail
Can I hv help on solving this?

a) In a mathematics class with 30 students, the teacher wants 2 different students to present the solutions to problems 3 & 5 on the board. In how many ways can the teacher assign the problems?
$\displaystyle {30 \choose 2}$

b) Find the number of ways in which a team of 6 bats-men, 4 bowlers and a wicket- keeper may be selected from a squad of 8 bats-men, 6 bowlers and 2 wicket-keepers.
$\displaystyle {8 \choose 6} {6 \choose 4} {2 \choose 1}$

why is that?

3. ## Thanks

Originally Posted by Jhevon
$\displaystyle {30 \choose 2}$

$\displaystyle {8 \choose 6} {6 \choose 4} {2 \choose 1}$

why is that?