Question

Tanya drives to work every day and passes two independently operated traffic lights. The probability that both lights are red is 0.55. The probability that the first light is red is 0.69. What is the probability that the second light is red, given that the first light is red? @jim_thompson5910 @mathstudent55 @SolomonZelman @zepdrix @aaronq @dan815 @abb0t @iambatman @zzr0ck3r

Answer 1

divide

Answer 2

0.55 by 0.69?

Answer 3

\[P(A|B)=\frac{P(A\cap B)}{P(B)}\]

Answer 4

yes

Answer 5

so, 0.797?? @satellite73

Answer 6

rounded to .80?

Answer 7

i don't know i didn't do it
hold on

Answer 8

yeah looks good
http://www.wolframalpha.com/input/?i=55%2F69

Answer 9

Thanks :))) @satellite73

Answer 10

@satellite73 Can I ask you another one?????????????