The probability that event A will occur is 20%. If event A occurs, the probability that event B will occur is 30%. What is the probability that event A will occur but event B will not?

1/10

7/55

5/36

7/50

5/24

I agree with OE here, but I do not agree with the solving method.

OE states:

The probability that event A will occur but event B will not = (the probability that event A will occur)*(1 - the probability that event B will occur) =

BUT: the solution is: 1/5*(1-0.3)=1/5*7/10=7/50.

May be I misinterpreted the question stem, but for me the probability that event B WILL occur is 1/5*0.3. Isn't it?

Please, help.

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