Students in a school were surveyed about their study habits. Forty-two percent of students said they study on weeknights and weekends, 47% said they studied on weekends, and 65% said they study either on weeknights or weekends. If you were to pick one student at random, what is the probability that he or she studies on a weeknight?

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Answer:

0.6 = 60% probability that he or she studies on a weeknight.

Step-by-step explanation:

We solve this question treating these events as Venn probabilities.

I am going to say that:

Probability A: Probability of a student studying on weeknights.

Probability B: Probability of a student studying on weekends.

Forty-two percent of students said they study on weeknights and weekends

This means that [tex]P(A \cap B) = 0.42[/tex]

47% said they studied on weekends

This means that [tex]P(B) = 0.47[/tex]

65% said they study either on weeknights or weekends.

This is [tex]P(A \cup B) = 0.65[/tex]

If you were to pick one student at random, what is the probability that he or she studies on a weeknight?

This is P(A), and the equation used is:

[tex]P(A \cup B) = P(A) + P(B) - P(A \cap B)[/tex]

Considering the values we have:

[tex]0.65 = P(A) + 0.47 - 0.42[/tex]

[tex]0.05 + P(A) = 0.65[/tex]

[tex]P(A) = 0.6[/tex]

0.6 = 60% probability that he or she studies on a weeknight.

Answer: 60% joaobezerra Is Right, and Confirmed by Buzz (Acceleration Education)

Step-by-step explanation:

We solve this question by treating these events as Venn probabilities. Forty-two percent of students said they study on weeknights and weekends. This means that 47% said they studied on weekends. This means that 65% said they study either on weeknights or weekends. This is If you were to pick one student at random, what is the probability that he or she studies on a weeknight?

0.6 = 60% that he or she studies on a weeknight.