So, no capitalists are altruists. So, no A are C. Next, construct a counterexample. No apples are oranges. All oranges are fruit. So, no apples are fruit.
Some intelligent people are highly immoral people.
All highly immoral people are unhappy people. Therefore, some unhappy people are not intelligent people. All oaks are plants. Therefore, some plants are not trees. Check to see that you have correctly translated the form.