Five marbles are randomly selected with replacement. The probability that a black marble is chosen is 15%. What is the probability that at least 2 marbles are black?

Question

anonymous · Answer

I don't know what that means. ^^^

anonymous · Answer

well if one marbel is 15% then two marbels would be 30%

anonymous · Answer

at least two are black, easier to compute 
none are black
one is black

then subtract the result from 1

anonymous · Answer

That's what I was thinking, but that isn't an option. @skinny23

anonymous · Answer

that is because it is wrong

anonymous · Answer

what are the options?

anonymous · Answer

probability that one is black is 15%
probability that one is not black is therefore 84% = .85

probability that none are black out of 5 picks is $.85^5$

anonymous · Answer

probability that exactly one is black is 
$$5\times .15\times .85^4$$

anonymous · Answer

your answer is therefore 
$$1-(.85)^5-5\times (.15)\times (.85)^4$$

anonymous · Answer

0.16, 0.14, 0.86, 0.84 are my options

anonymous · Answer

So I would get 0.16? @satellite73