## ANS:

**a.**

The probability that the randomly selected vehicle used a toll pass is:

```
Total vehicles with toll pass / Total vehicles
= 542 + 946 / 872 + 1601
= 1488 / 2473
= **0.602** (round to 4 decimal places)
```

**b.**

The probability that the vehicle used a toll pass, given that the vehicle is a car, is:

```
Total cars with toll pass / Total cars
= 542 / 872
= **0.62** (round to 4 decimal places)
```

Therefore, the answer is:

a. 0.602 b. 0.62