Hello, lebanon!

A driver makes same trip everyday.he meets three trafic lights on trip.

A study established that :

. . the probability of meeting three red lights is 0.2

. . the probability of meeting at least one red light is 0.8

. . the probability of meeting one red light is 0.3.

We are given:

. .

. .

. .

Find the probability:

(a) meets exactly two red lights

. . . . . . . . . . . . .

(b) does not meet a red light

The opposite of "no red lights" is "at least one red light".

(c) meets at most one red light.

"At most one red light" means: "no red lights" or "one red light".