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What is the probability that a student randomly selected from a class https://gmatclub.com/forum/whatistheprobabilitythatastudentrandomlyselectedfromaclassof42isaboywithblackeyes278215.html 
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Author:  pushpitkc [ 05 Oct 2018, 21:44 ] 
Post subject:  What is the probability that a student randomly selected from a class 
What is the probability that a student randomly selected from a class of 42 is a boy with black eyes? 1. Half the students in the class are boys 2. Onethird of the students in the class have black eyes. Source: Experts Global 
Author:  DavidTutorexamPAL [ 05 Oct 2018, 22:03 ] 
Post subject:  Re: What is the probability that a student randomly selected from a class 
pushpitkc wrote: What is the probability that a student randomly selected from a class of 42 is a boy with black eyes? 1. Half the students in the class are boys 2. Onethird of the students in the class have black eyes. Source: Experts Global To answer the question we need to know the number of students who are both boys and have black eyes. We'll look for statements that give us this information, a Logical approach. (1) No information on black eyes. Insufficient. (2) No information on boys. Insufficient. Combined: No information on the overlap between 'boys' and 'black eyes' (there could be maximal overlap = 1/3 * 42 or there could be no overlap at all) Insufficient. (E) is our answer. 
Author:  AN1728 [ 22 Dec 2022, 23:02 ] 
Post subject:  What is the probability that a student randomly selected from a class 
To answer this question let us go step wise in trying to arrive at the solution. (1) No information on black eyes. Notice that the statement does not talk about the number of students with black eyes and therefore it is not possible for us to make any conclusions on the number of black eyed boys. (2) No information on boys. Taken independently the statement provides no information with reference to the number of boys that are there in the class. So for all we know they might just as well be only girls in the class. Hence A,D &B are all ruled out as options Hence the correct choice is either C or E. If both the statements are taken together even in such kind of circumstance, We cannot determine the number of boys who have black eyes, because we do not know whether the instance of black eyes is mutually exclusive to that of a person being a boy. For all we know they could be two mutually exclusive events. Hence, the correct option E. Posted from my mobile device 
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