Question

Martha drives to work every day and passes two independently operated traffic lights. The probability that both lights are green is 0.31. The probability that the first light is green is 0.51. What is the probability that the second light is green, given that the first light is green?

Answer 1

A. 0.61

Explanation:

P(A)•P(B)=0.31

0.51•P(B)=0.31

P(B)=0.31/0.51=0.608

Rounded: 0.61

Answer 2

P(A)•P(B)=0.31
0.51•P(B)=0.31
P(B)=0.31/0.51=0.608