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# Probability - binomial distribution equation watch

1. Hey guys,

I am just wondering if someone can give me a bit of help with this binomial distribution probability question. I think I have taken something relatively simple and totally overcomplicated it, so simple explanations and step by step process would be ideal.

A bowl contains 2 cubes, a white and a black. Pick one at random, then return to the bowl. Do this a total of four times. Using the binomial distribution equation find the probability of ...

a) picking a white cube 4 times
b) picking a white cube 3 times
c) never picking a white cube

Please talk through each step as I have really confused myself now. Thank you!
2. (Original post by krisa14)
Hey guys,

I am just wondering if someone can give me a bit of help with this binomial distribution probability question. I think I have taken something relatively simple and totally overcomplicated it, so simple explanations and step by step process would be ideal.

A bowl contains 2 cubes, a white and a black. Pick one at random, then return to the bowl. Do this a total of four times. Using the binomial distribution equation find the probability of ...

a) picking a white cube 4 times
b) picking a white cube 3 times
c) never picking a white cube

Please talk through each step as I have really confused myself now. Thank you!
Let X denote the number of times a white cube is picked so X - B(4, 0.5) (the 0.5 probability is only true if the cubes are the same size but they probably just expect you to assume equal probability and not think about that)

Then just plug into the formulas.

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