Kim eats out with friends on 70% of all Friday evenings.She goes to see a film on 15% of all Friday evenings.On 10 percent of all Friday evenings, she eats out with friends and goes to see a film.On any Friday, what is the probability that Kim eats out with friends, goes to see a film, or both?
A)10.5%
B)25%
C)75%
D)85%
E)100%

Question

Quizplus · Accepted Answer

The probability that Kim eats out with friends, goes to see a film, or both can be calculated using the formula for the union of two events: P(A or B) = P(A) + P(B) - P(A and B). Here, P(A) = 70% (eats out with friends), P(B) = 15% (goes to see a film), and P(A and B) = 10% (eats out and sees a film). Thus, P(A or B) = 70% + 15% - 10% = 75%.

Kim Eats Out with Friends on 70% of All Friday