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The probability that event M will not occur is 0.8 and the probability
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15 Jun 2016, 01:32
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The probability that event M will not occur is 0.8 and the probability that event R will not occur is 0.6. If events M and R cannot both occur, which of the following is the probability that either event M or event R will occur? A) 1/5 B) 2/5 C) 3/5 D) 4/5 E) 12/25
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The probability that event M will not occur is 0.8 and the probability
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11 Oct 2016, 16:59
Bunuel wrote: The probability that event M will not occur is 0.8 and the probability that event R will not occur is 0.6. If events M and R cannot both occur, which of the following is the probability that either event M or event R will occur?
A) 1/5 B) 2/5 C) 3/5 D) 4/5 E) 12/25 We are given that the probability that event M will not occur is 0.8 and the probability that event R will not occur is 0.6 and that events M and R cannot both occur. We need to determine the probability that either event M or event R will occur. The probability that event M will occur is 1  0.8 = 0.2 = 1/5 The probability that event R will occur is 1  0.6 = 0.4 = 2/5 Since events M and R cannot both occur , the probability that either event M or event R will occur is 1/5 + 2/5 =3/5. Answer: C
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Re: The probability that event M will not occur is 0.8 and the probability
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15 Jun 2016, 04:04
Bunuel wrote: The probability that event M will not occur is 0.8 and the probability that event R will not occur is 0.6. If events M and R cannot both occur, which of the following is the probability that either event M or event R will occur?
A) 1/5 B) 2/5 C) 3/5 D) 4/5 E) 12/25 P(R) = 1  0.8= 0.2 P(M) = 1 0.6 = 0.4 Given that both events are mutually exclusive. Prob that either event M or event R will occur = 0.2+0.4 = 0.6 = (6/10) = (3/5) C is the answer.




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The probability that event M will not occur is 0.8 and the probability
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Updated on: 15 Jun 2016, 04:31
p(m) =0.2 p(r) =0.4 p(m intersection r) = 0 (If events M and R cannot both occur) p(m or r) = 0.2+0.4 =0.6
Corrected !!
Originally posted by CounterSniper on 15 Jun 2016, 03:52.
Last edited by CounterSniper on 15 Jun 2016, 04:31, edited 1 time in total.



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Re: The probability that event M will not occur is 0.8 and the probability
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15 Jun 2016, 23:07
Got it wrong.
p(m) =0.2 p(r) =0.4
So, I calculated probability as sum of:
i) m occurs but r does not occur = 0.2*0.6 ii) r occurs but m does not occur = 0.4*0.8
So, probability = 0.2*0.6 + 0.4*0.8 = 0.44 = 11/25!



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Re: The probability that event M will not occur is 0.8 and the probability
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03 Jul 2016, 14:34
Just made a mistake by multiplying 0.2 and 0.4, got \(\frac{2}{25}\) Note to self: "multiply" when there is an "AND", and "add" when there is an "OR" we should be adding 0.2+0.4 = 0.6 or \(\frac{3}{5}\)
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Re: The probability that event M will not occur is 0.8 and the probability
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26 Sep 2016, 18:55
Can someone please explain why is it not 0.8*0.4+0.2*0.6 11/25



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Re: The probability that event M will not occur is 0.8 and the probability
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10 Oct 2016, 00:53
shonakshi wrote: Can someone please explain why is it not 0.8*0.4+0.2*0.6 11/25 I think , you are trying to calculate probability by multiplying P(M)*P(~R) + P(R)*P(~M) . This is wrong . Formula is P(M or R) = P(M) + P(R)  P (M and R) => 0.2 + 0.4  0 = > 0.6 or 3/5 (Answer is C) .



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The probability that event M will not occur is 0.8 and the probability
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10 Oct 2016, 07:58
shonakshi wrote: Can someone please explain why is it not 0.8*0.4+0.2*0.6 11/25 Go through this page, it will answer all your queries... https://people.richland.edu/james/lectu ... 5rul.htmlHope that helps..
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Re: The probability that event M will not occur is 0.8 and the probability
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13 Oct 2016, 05:01
ScottTargetTestPrep wrote: Bunuel wrote: The probability that event M will not occur is 0.8 and the probability that event R will not occur is 0.6. If events M and R cannot both occur, which of the following is the probability that either event M or event R will occur?
A) 1/5 B) 2/5 C) 3/5 D) 4/5 E) 12/25 We are given that the probability that event M will not occur is 0.8 and the probability that event R will not occur is 0.6 and that events M and R cannot both occur. We need to determine the probability that either event M or event R will occur. The probability that event M will occur is 1  0.8 = 0.2 = 1/5 The probability that event R will occur is 1  0.6 = 0.4 = 2/5 Since events M and R cannot both occur , the probability that either event M or event R will occur is 1/5 + 2/5 =3/5. Answer: C We should take into consideration that both cannot occurs. please explain



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Re: The probability that event M will not occur is 0.8 and the probability
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13 Oct 2016, 07:44
Bunuel wrote: The probability that event M will not occur is 0.8 and the probability that event R will not occur is 0.6.If events M and R cannot both occur, which of the following is the probability that either event M or event R will occur?
A) 1/5 B) 2/5 C) 3/5 D) 4/5 E) 12/25 M' = 0.80 So M = 0.20 R' = 0.60 So R = 0.40 Quote: probability that either event M or event R will occur? M+R = M + R  MR Quote: events M and R cannot both occur So , MR = 0 M+R = 0.20 + 0.40  0 Or, M+R = 0.60 Hence answer will be 0.60 or (C) 3/5 SOHAM6185 wrote: We should take into consideration that both cannot occurs. please explain The reason is highlighted... Try to solve this question using VENN Diagram approach it will be crystal clear...
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Re: The probability that event M will not occur is 0.8 and the probability
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30 Jun 2017, 03:45
sb0541 wrote: shonakshi wrote: Can someone please explain why is it not 0.8*0.4+0.2*0.6 11/25 I think , you are trying to calculate probability by multiplying P(M)*P(~R) + P(R)*P(~M) . This is wrong . Formula is P(M or R) = P(M) + P(R)  P (M and R) => 0.2 + 0.4  0 = > 0.6 or 3/5 (Answer is C) . yes, that is why p(m and n) need to be zero.



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Re: The probability that event M will not occur is 0.8 and the probability
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08 Nov 2017, 17:00
shonakshi wrote: Can someone please explain why is it not 0.8*0.4+0.2*0.6 11/25 The probability that event M will not occur is 0.8 and the probability that event R will not occur is 0.6. If events M and R cannot both occur, which of the following is the probability that either event M or event R will occur? Let's break this down M will not occur = 0.8; M will occur = 0.2 R will not occur = 0.6; R will occur = 0.4 P(M or R) = P(M) + P(R)  P (M and R) P(M or R) = 0.2 + 0.4  0 P(M or R) = 0.6 = 6/10 = 3/5 Note: Multiplying occurrence that will not occur + Multiplying occurrence that will occur is not equal to either event M or event R will occur



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Re: The probability that event M will not occur is 0.8 and the probability
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11 Mar 2018, 20:57
shonakshi wrote: Can someone please explain why is it not 0.8*0.4+0.2*0.6 11/25 Once you say that event M and event R can not occur together , it means that both are mutually exclusive. P(M).P(R)=0 Posted from my mobile devicePosted from my mobile device



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Re: The probability that event M will not occur is 0.8 and the probability
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14 Mar 2018, 08:18
be careful there are 2 cases case 1 1= p (a happen)+ p (b happen) p (both a and b happen) +p (neither a nor b happen) . this is ven digram
case 2 1= p (a dose not happen)+ p(b dose not happen) p (neither a nor b happen)+ p (both a and b happen). this is ven diagram p ( only a happen) is in p (b dose not happen).
so, there is two scenario here.



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Re: The probability that event M will not occur is 0.8 and the probability
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24 Aug 2018, 08:07
GMATSkilled wrote: shonakshi wrote: Can someone please explain why is it not 0.8*0.4+0.2*0.6 11/25 The probability that event M will not occur is 0.8 and the probability that event R will not occur is 0.6. If events M and R cannot both occur, which of the following is the probability that either event M or event R will occur? Let's break this down M will not occur = 0.8; M will occur = 0.2 R will not occur = 0.6; R will occur = 0.4 P(M or R) = P(M) + P(R)  P (M and R) P(M or R) = 0.2 + 0.4  0 P(M or R) = 0.6 = 6/10 = 3/5 Note: Multiplying occurrence that will not occur + Multiplying occurrence that will occur is not equal to either event M or event R will occur How can that formula be correct? What if the problem had said the probability that M will not occur is .5, and the probability that R will not occur is .5. Then according to your formula, you'd have: P(M or R) = P(M) + P(R)  P(M and R) P(M or R) = .5 + .5  0 P(M or R) = 1 So if two mutually exclusive events each have a 1/2 probability of occurring, then the probability of at least one of them occurring is 1 (100% of the time?) That doesn't make any sense to me, so I'm not exactly sure why that formula is what you're supposed to apply. In a reallife scenario, that's like saying the Cardinals have a 40% chance to win the World Series, and the Yankees have a 20% chance to win, so the chance that one of them wins is 60% (since both of them cannot win)... Which doesn't make any sense. Again, what if you said the cardinals have an 80% chance to win and the Yankees have a 30% chance to win. So the chance that one of them wins is 110%? The language in the question doesn't seem to suggest that either M or N must occur... In order to interpret the question the way the answer seems to, I would think the language would have to say something like "Out of 100 trials, M did not occur 80% of the time and N did not occur 60% of the time; if N and M never occurred on the same trial, what's the probability that a randomly selected trial will have M OR N occurring?" In that case, when you already have a list of events that happened, you could apply the formula P(M or R) = P(M) + P(R)  P(M and R)... Take it back to the 50% example, if you know that M occurred 50% of the time and N occurred 50% of the time, and M and N cannot happen, then you know that at least M or N had to happen every time. But when you're talking about the probability of a future event, as the problem seems to suggest, it doesn't make sense to just add the probabilities. Can someone tell me if/how my reasoning is incorrect?



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Re: The probability that event M will not occur is 0.8 and the probability
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14 Sep 2018, 18:49
Can someone please address the above challenge to this question's answer? I also disagree with the application of the formula used in the solution. This question is posing a future probability event.
What if the question was modified to probability of M occurring=90% and R occurring=90%? (So not occurring for either event is 10%). M and R are still mutually exclusive events.
If we apply the recommended formula P(M or R)=P(M) + P(R) P(M and R), we get .9+.90=1.8. Wait, 1.8!? That doesn't even make sense.



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Re: The probability that event M will not occur is 0.8 and the probability
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24 Oct 2018, 10:43
bluenux wrote: Can someone please address the above challenge to this question's answer? I also disagree with the application of the formula used in the solution. This question is posing a future probability event.
What if the question was modified to probability of M occurring=90% and R occurring=90%? (So not occurring for either event is 10%). M and R are still mutually exclusive events.
If we apply the recommended formula P(M or R)=P(M) + P(R) P(M and R), we get .9+.90=1.8. Wait, 1.8!? That doesn't even make sense. Both can't occur at the same time means they're mutually exclusive events. Only M or R can happen, but not both! Therefore, you don't have to subtract the probabilty for P(M and R) > P(M or R) = P(M) + P(R) > P(M) = 0.2 > P(R) = 0.4 > P(M or R) = 0.2 + 0.4 = 0.6 = 3/5



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Re: The probability that event M will not occur is 0.8 and the probability
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24 Oct 2018, 12:34
mskx wrote: bluenux wrote: Can someone please address the above challenge to this question's answer? I also disagree with the application of the formula used in the solution. This question is posing a future probability event.
What if the question was modified to probability of M occurring=90% and R occurring=90%? (So not occurring for either event is 10%). M and R are still mutually exclusive events.
If we apply the recommended formula P(M or R)=P(M) + P(R) P(M and R), we get .9+.90=1.8. Wait, 1.8!? That doesn't even make sense. Both can't occur at the same time means they're mutually exclusive events. Only M or R can happen, but not both! Therefore, you don't have to subtract the probabilty for P(M and R) > P(M or R) = P(M) + P(R) > P(M) = 0.2 > P(R) = 0.4 > P(M or R) = 0.2 + 0.4 = 0.6 = 3/5 I recognize that point, which is why my calculation equated 0 for P(M and R). The confusion still stands...



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Re: The probability that event M will not occur is 0.8 and the probability
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24 Oct 2018, 12:44
bluenux wrote: mskx wrote: bluenux wrote: Can someone please address the above challenge to this question's answer? I also disagree with the application of the formula used in the solution. This question is posing a future probability event.
What if the question was modified to probability of M occurring=90% and R occurring=90%? (So not occurring for either event is 10%). M and R are still mutually exclusive events.
If we apply the recommended formula P(M or R)=P(M) + P(R) P(M and R), we get .9+.90=1.8. Wait, 1.8!? That doesn't even make sense. Both can't occur at the same time means they're mutually exclusive events. Only M or R can happen, but not both! Therefore, you don't have to subtract the probabilty for P(M and R) > P(M or R) = P(M) + P(R) > P(M) = 0.2 > P(R) = 0.4 > P(M or R) = 0.2 + 0.4 = 0.6 = 3/5 I recognize that point, which is why my calculation equated 0 for P(M and R). The confusion still stands... How to you calculate P(M and R) that you get 0? or means add and means multiply To stay with your example: P(M or R) = P(M) + P(R)  P(M and R) P(M or R) = P(0.9) + P(0.9)  P(0.9*0.9) > 0.9*0.9 is not 0 But please consider that P(M or R) = P(M) + P(R) P(M and R) is wrong because its a mutually exclusive event.




Re: The probability that event M will not occur is 0.8 and the probability
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