2. In an animal-behaviour study, hamsters were tested with a number of intelligence tasks, as shown in the table bellow. If a hamster is randomly chosen from this study group, what is the likelihood that the hamster has participated in:

a) Exactly three tests? b) Fewer than two tests? c) Either one or two tests? d) No test or more than three tests?

Number of tasks --------------- Number of hamsters

0 10

1 6

2 4

3 3

4 or more 5