Answer:
P(at least 3) = 0.35
Explanation:
We are given the following probability distribution in the question:
x: 0 1 2 3 4 5
P(x): 0.10 0.25 0.30 0.20 0.10 0.05
where x is the number of customers in line at a supermarket
Verification for a discrete probability distribution:

Hence, it is a discrete probability distribution.
We have to evaluate P(at least 3).

Thus,
P(at least 3) = 0.35
0.35 is the probability that there are atleast 3 customers in line at a supermarket.