Question??
Dr. Sox drives through two stoplights on her way to work. The first light is green for 20 seconds out of each minute. The second light is green for 35 seconds out of each minute. What is the probability that Dr. Sox will hit two green lights?
Explanation;
Since this is an AND situation, we MULTIPLY the probabilities.
Answer/Explanation:
First light green:
P
1
=
20
60
=
1
3
Second light green:
P
2
=
35
60
=
7
12
Both lights green:
P
=
P
1
×
P
2
=
1
3
×
7
12
=
7
36
Of course, this is assuming that there is no "green wave" policy, or the two probabilities would not be independent