On average, 60% of trucks and 40% of cars pass by a gas station per day. The probability of a truck stopping

On average, 60% of trucks and 40% of cars pass by a gas station per day. The probability of a truck stopping for refueling is 0.2, while for a passenger car this probability is 0.1. Find the probability that the car will stop for a gas station.

Here, as far as I understand, you need to solve through the sum of the probabilities of two cases
Here is the formula:
P (C) = P (A) + P (B)

The big event is the car will stop.
It turns out that either a cargo or a passenger
Substitute in the formula and get:
P (C) = cargo or passenger
Or – addition
We get:
P (C) = P (g) + P (l)

P (r) = 0.2
P (l) = 0.1

Now we substitute in our formula:
P (C) = 0.2 + 0.1 = 0.3