IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Math => Topic started by: joel on April 16, 2010, 09:57:08 am

Title: STATASTICS DOUT
Post by: joel on April 16, 2010, 09:57:08 am

The probability of an event A occurs is P(A) = 0.3 The event B is independent of A and P(B) = 0.4.

Calculate P(A or B or both occur).

The answer is 0.58.

I would like to to know how to arrive at this answer.

The question is from Cambridge Advanced Level Mathematics Statistics 1 by Steve Dobbs and Jane Miller, Miscellaneous Exercise 4, Question 2 part (a).

Can someone please explain how to arrive at the answer.   

Title: Re: STATASTICS DOUT
Post by: T.Q on April 16, 2010, 10:12:30 am

dont double post

just post in the right place once , and we will see it

Title: Re: STATASTICS DOUT
Post by: holtadit on April 16, 2010, 10:16:51 am

I get 0.82

Are you sure 0.58 is the right answer ? Just check again.

Title: Re: STATASTICS DOUT
Post by: joel on April 16, 2010, 02:15:38 pm

Yes I sure...

Title: Re: STATASTICS DOUT
Post by: astarmathsandphysics on April 16, 2010, 05:25:45 pm

P(aub)=p(a)+p(b)-p(anb) with p(anb)=p(a)*p(b) cos a and b are independent.