Studying Online This table presents the number of girls and boys who prefer or do not prefer studying online. Girls Boys Row total Want the option to keep studying online 10 3 13 Don’t want the option to keep studying online 5 7 12 Column total 15 10 25 Which mathematical sentence can be used to calculate the probability of selecting a student who wants the option to keep studying online or is a boy? (1 point) Responses 1325+1025−325 Start Fraction 13 over 25 End Fraction plus Start Fraction 10 over 25 End Fraction minus Start Fraction 3 over 25 End Fraction 325 Start Fraction 3 over 25 Endfraction 1325×1025 Start Fraction 13 over 25 End Fraction times Start Fraction 10 over 25 End Fraction 1325+1025

1 answer

To find the probability of selecting a student who wants the option to keep studying online or is a boy, we can use the principle of inclusion-exclusion.

Let:

  • \( P(A) \): Probability that a student wants to keep studying online.
  • \( P(B) \): Probability that a student is a boy.
  • \( P(A \cap B) \): Probability that a student is both wanting to keep studying online and is a boy.

From the table:

  • Total number of students = 25
  • Number of students that want the option to keep studying online \( (A) = 13 \)
  • Number of boys \( (B) = 10 \)
  • Number of students that want to study online and are boys \( (A \cap B) = 3 \)

The probabilities are:

  • \( P(A) = \frac{13}{25} \)
  • \( P(B) = \frac{10}{25} \)
  • \( P(A \cap B) = \frac{3}{25} \)

Using the inclusion-exclusion principle, the probability that a student either wants to study online or is a boy is calculated as follows:

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

Substituting in the values we have:

\[ P(A \cup B) = \frac{13}{25} + \frac{10}{25} - \frac{3}{25} = \frac{13 + 10 - 3}{25} = \frac{20}{25} \]

So the mathematical sentence that could be used is:

\[ \frac{13}{25} + \frac{10}{25} - \frac{3}{25} \]

This corresponds to the option:

\( \frac{13}{25} + \frac{10}{25} - \frac{3}{25} \).