If no birds can swim and all penguins are birds, which of the following statements must be true?*No penguins can swim.Some birds can swim.All birds are penguins.Some penguins can fly.Cannot say

The statement that must be true is "No penguins can swim."

Here's the step-by-step reasoning:

1. The first premise is "No birds can swim." This is a universal negative statement, meaning it applies to all birds without exception.

2. The second premise is "All penguins are birds." This is a universal affirmative statement, meaning every penguin is a bird.

3. If all penguins are birds, and no birds can swim, then it logically follows that no penguins can swim. This is because the group of penguins is included in the group of birds, and if no members of the larger group (birds) can swim, then no members of the smaller group (penguins) can swim either.

The other statements ("Some birds can swim," "All birds are penguins," "Some penguins can fly") are not necessarily true based on the given premises. For example, we don't know whether some birds can swim or some penguins can fly because the premises don't provide this information. And the statement "All birds are penguins" is definitely not true because the second premise only says that all penguins are birds, not the other way around.

The statement that must be true is "No penguins can swim." Here's why:

1. The problem states that "no birds can swim." This is a universal negative, meaning it applies to all birds without exception.

2. The problem also states that "all penguins are birds." This is a universal affirmative, meaning every penguin is a bird.

3. Therefore, if no birds can swim and all penguins are birds, it follows logically that no penguins can swim. If a penguin could swim, it would contradict the statement that no birds can swim.

The other statements are not necessarily true based on the information given. We don't know if some birds can swim, if all birds are penguins, or if some penguins can fly. The statement "Cannot say" is not true because we can determine from the given information that no penguins can swim.