The probability of Dawn reading before going to bed is 5/6. The probability of Dawn brushing her teeth before going to bed is 6/7. The probability of Dawn watching TV before going to bed is 1/5. What is the probability that she will do all three activities before going to bed?
A.2/3
B.5/7
C.2/35
D.1/7

Question

The probability of Dawn reading before going to bed is 5/6. The probability of Dawn brushing her teeth before going to bed is 6/7. The probability of Dawn watching TV before going to bed is 1/5. What is the probability that she will do all three activities before going to bed?
A.2/3
B.5/7
C.2/35
D.1/7

anonymous · Answer

making the rather broad and erroneous assumption that these events are independent, you can multipy the probabilities together

hero · Answer

Hint:

When three events, A and B and C, are independent, the probability of all three occurring is: 
P(A and B and C) = P(A) · P(B) · P(C)

hero · Answer

Why wouldn't they be independent?

hero · Answer

@satellite73

anonymous · Answer

30/210.... so that needs to be reduce?

hero · Answer

30/210 = 3/21 = 1/7

anonymous · Answer

oh.... ok that makes sense. Thanks!