## anonymous 4 years ago Scott has eight CDs, and he picks two to take to work each day. How many different ways can Scott choose two CDs? a.)56 B.)28 C.)20,160 D.)112

1. anonymous

$\frac{8\times 7}{2}$

2. anonymous

$${8 \choose 2} =28$$ so, B is correct.

3. anonymous

8 choices for first one, then 7 for second one, and since order doesn't matter you divide by 2 because there is no difference between picking first slayer and then britney spears, or first britney spears and then slayer

4. perl

pop culture reference :O

5. perl

you divide by 2 because you have overcounted twice as much,