Dear entropyyy,

Your idea is correct but your expression is incorrect. You have to

**add** the probability of all three turning left.

That is, Probability that at least two cars turning left=

Although the answer is obtained I would like you to show how the problem could be solved in a more methodical way.

Using our abbrevations,

Event that at least two cars turn left=

Since the two events

are mutually exclusive,

Probability that at least two cars turn left=

Since A,B,C and A,B,D are independent,

Probability that at least two cars turn left=

Probability that at least two cars turn left=

Hope this will help you.