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# Probability distribution question watch

1. A fair five-sided spinner is spun(2 red, 1 yellow, 2 blue)
Given that the spinner is spun 5 times, write down, in table form, the probability distributions of the following random variables:

a)X, the number of times red appears.
b)Y, the number of times yellow appears.

I drew the correct table, however my values for P(X=x) were incorrect.
E.g. for red appearing 2 times, I did the (2/5)^2 multiplied by (3/5)^2. The answer also contains this step but for some reason further multiplies it by 10??
2. 10 is the number of possibilites of getting R in different arrangements

e.g RRYBB, RYBBR, YRRBB etc

You work this out by using the nCr button. In this case it will be 5C2 because it's spun 5 times and theres 2 reds
3. (Original post by amaraub)
10 is the number of possibilites of getting R in different arrangements

e.g RRYBB, RYBBR, YRRBB etc

You work this out by using the nCr button. In this case it will be 5C2 because it's spun 5 times and theres 2 reds
Oh thanks. Hadn't come across until now..interesting.

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