Answer:
A) about 1 pet
Explanation:
Total the products of number of pets and their probability.
... 0×0.4 +1×0.3 +2×0.25 +3×0.05
... = 0 +0.3 +0.5 +0.15 = 0.95 . . . . . about 1
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We assume that "3 or more" will be closer to 3 than to 15, a number that would raise the expected value to more than 1.5.