Girls. Boys. Row total.
10. 3. 13. Want to study online
5. 7. 12. Don't want to study online
15. 10. 25. Column total
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?
A. 13/25 + 10/25
B. 11/25 + 10/25 - 3/25
C. 3/25
D. 13/25 * 10/25
B. 11/25 + 10/25 - 3/25
First, find the probability of selecting a student who wants to study online: 13/25
Next, find the probability of selecting a boy: 10/25
Finally, find the probability of selecting a student who wants the option to keep studying online or is a boy by adding the two probabilities and subtracting the probability of a boy who wants to study online: 13/25 + 10/25 - 3/25 = 20/25 = 4/5