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So You Think You Know Probability?

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AoA everyone....so im currently doing S1 and I have a lot of problems especially in probability..It seems like no matter how many questions I do, there always comes a question that im unable to do...i mean most of the questions.So basically I need help. Is there anyone out there who can do Miscellaneous Exercise 4 Q. no. 1&2 (from the cambridge S1 book)? Help me out guys...
 
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It would be better if you typed the question so that you may receive your answer quicker :)
 
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Alright here it goes....
The probability that 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).
 
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probability of A = 0.3
probability of B= 0.4

either A comes OR B = 0.3 + 0.4
= 0.7

A and B both come together = 0.3 x 0.4 = 0.12

then we add both probabilities : so 0.7 + 0.12 = 0.82

is 0.82 right??
 
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AoA everyone....so im currently doing S1 and I have a lot of problems especially in probability..It seems like no matter how many questions I do, there always comes a question that im unable to do...i mean most of the questions.So basically I need help. Is there anyone out there who can do Miscellaneous Exercise 4 Q. no. 1&2 (from the cambridge S1 book)? Help me out guys...

Have you considered doing M1 instead of S1? Probability is weird. Some people can do it and some can not. It is like those that cannot do not have the wiring in their brains that is necessary for them to easily picture and solve the problems. For me there is no comparison between doing M1 and S1. I would do M1 standing on my head rather than do S1 siting at a comfortable desk.
 
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P(A or B or both occur) signifies P(AUB) as in set....................
so u have the formula P(AUB) = P(A) + P(B) - P(A n B)
same formula applies here too
P(A or B or both occur) = P(A) + P(B) - P(A and B)
=0.3 + 0.4 - 0.12
=0.58
 
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P(A or B or both occur) signifies P(AUB) as in set....................
so u have the formula P(AUB) = P(A) + P(B) - P(A n B)
same formula applies here too
P(A or B or both occur) = P(A) + P(B) - P(A and B)
=0.3 + 0.4 - 0.12
=0.58
Thank you! I had a doubt in the same problem. But why dont they show this in the textbook??
 
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