anonymous one year ago A box of 15 parts contains 7 that are defective. A worker picks parts one at a time and attempts to install them. Find the probability of each outcome in​ (a) through​ (d). ​(a) The first two chosen are both good. nothing ​(Round to four decimal places as​ needed.)

1. mathmate

Please check your question, which probably contains typo(s) and incomplete. Cannot have 15 parts of which 77 are defective.

2. anonymous

it a 7

3. anonymous

P(two are good) $=\frac{C _{2}^{8} }{C_{2}^{15} }$=?

4. anonymous

30

5. anonymous

ok im so lost 8/15

6. anonymous

and 054

7. anonymous

pl help me out

8. anonymous

im so lost and dum

9. mathmate

(a) Initially, there are 8 good out of 15, so probability of getting the first good one is 8/15. For the next one, there are only 7 good out of 14, so probability is 7/14. For this two step experiment, the probability of getting 2 good out of two is therefore (8/15)*(7/14)=4/15. Alternatively, you could use the formula by @Surjithayer