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# Binomial distribution watch

1. A lab is growing culture on 100 slides, the probability of a culture being obvious after 4 hours is 1/10

What is the probability of selecting 2 slides with obvious culture after 4 hours when a sample of 15 is taken?

My working so far:

n = 15
p = 0.1
q = 0.9

Therefore; 0.1^2 x 0.9^13

=2.54x10-3

0.00254
Edit: its ok, solved it
2. So let's knock it off "unanswered questions"

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