There are 32 cars, 20 trucks and 8 vans in the parking lot. Find the probability that once a car or truck leaves the lot, the next vehicle leaving is a van. What is the answer?

There are 8 vans and 52 non-vans. Given that a non-van leaves, there are 8 vans and 51 non-vans, or 59 vehicles in total.

Hence, the probability that a van leaves next is 8/59.