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# Maths s1 urgent question on binomials in paper

1. 7bii) may2009 st : "calculate the probrability, when sorting a batch of 35 letters, mrs fewer sorts atleast one letter incorrectly. This is a binomial distribution question, but I have no idea how to go about it, since n=35 table isn't in the formula booklet, and I've tried using the formula, (using x=0 and x=1) but the answer made no sense. I couldn't understand the markscheme either. Thanks for any replies!! (P=0.06) for this. Each sorting of a letter may be assumed to be in dependant.
2. Just work out the probabality she sorts none incorrectly and subtract the answer from 1, atleast this is what i'd do, not sure if it's correct :/
3. (Original post by CallumTM)
Just work out the probabality she sorts none incorrectly and subtract the answer from 1, atleast this is what i'd do, not sure if it's correct :/
Thats what I did, I substituted x=0 and got 1 as the answer but that cant be right?
4. The distribution of wrongly sorted letters is
Bin(35,0.06)

The chance of zero mistakes is
35C0*(0.06)0*(0.94)35

Then subtract from 1

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