Question

Marley drives to work every day and passes two independently operated traffic lights. The probability that both lights are red is 0.35. The probability that the first light is red is 0.48. What is the probability that the second light is red, given that the first light is red?

Answer 1

@perl @dan815

Answer 2

I will label
R1 = first light is red
R2 = second light is red

P(R1 & R2)= 0.35
P(R1) = 0.48
You want to find P( R2 | R1)

Answer 3

Lets use the conditional probability formula
P( R2 | R1 ) = P( R2 & R1 ) / P(R1)

Answer 4

So P ( R2 | R1) = 0.35/0.48 ?

Answer 5

Thank you

Answer 6

correct