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#9 "One person is to be selected..."

edited Wed Aug 16, 2017 2:59 am in Q1
fontainedfontained Joined: 07/22/2017Posts: 23
From the practice test that you gave us the link to in our online class. From "Practice Book for the PBT GRE..." question #9




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  • Jonathan EvansJonathan Evans PowerScore Staff Joined: 10/31/2016Posts: 97
    This is a memorable question, one that students often ask about.

    Approach this with a step-by-step approach. Start with the basic principles of probability. We are looking for a fraction (part to whole relationship). Remember that the numerator is the "desired outcomes" and the denominator "total possible outcomes."

    Here, we have a 44 % chance it's a male; that means 44 out of 100 chance. However, there are only 25 people in the group.

    So we need to ask ourselves how could we convert 44 / 100 to some number out of 25. We could set up an equation:

    44/100 = x/25

    Or we could notice that if we have a 44 out of 100 chance of getting a dude, we could reduce this down first to 22 out of 50 and then 11 out of 25.

    Thus we have 11 men out of 25 total. 

    By the same principle, we can note that we have a 28 out of 100 chance of getting a male born before 1960. Reduce this to get 14 out of 50 and then 7 out of 25. Thus we have 7 men born before 1960.

    Given that there are 11 men total, this means we have 4 men born after 1960.

    Therefore, the answer is C.

    I hope this helps!
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