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At a party, there are 30 men, 16 of whom are without dates, and 30 women, none of of whom are without dates. Find the probability of picking someone at random and getting a person who is a woman or without a date?

User Sir Mbuki
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1 Answer

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For this type of probability question, there are different ways to solve the same question but let's analyze the situation and calculate as simple as possible.

For our question, there are two parts, the first one first is the probability to pick someone who is a woman. Once there are 60 people of which 30 are women, it means this probability is 30/60. Let's keep this probability.

Now let's move on to the second part. The situation where we pick someone who is without a date. once there are 60 people and all 30 women have a date and 16 men also have a date it means 30 + 16 - 60 = 14 people does not have a date. So the probability to pick someone without a date is 14/60.

Now once we have analyzed the two parts of the question, and we have two probabilities all we need is to sum our probabilities, as follows:

But why do we sum and do not multiply? Because we use the proposition OR at "Find the probability of picking someone at random and getting a person who is a woman OR without a date" If the proposition was AND we would have multiplied both probabilities.

At a party, there are 30 men, 16 of whom are without dates, and 30 women, none of-example-1
User Jhernandez
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