help on section 2.7 A and B

Proving Invalidity and Proving Validity 77 chile and gave up; we saw that it would be impossible for there to be a counterexample that any way of making the premises true would have to make the conclusion true as wel Exercises 2.7 A. Use Euler diagrams to determine whether the following are valid or invalid: 1 All As are Bs. No Bs are Cs. Therefore, no As are Cs. 2 Some As are Bs. No Bs are Cs. Therefore, some As are not Cs. 3 No As are Bs. No Bs are Cs. Therefore, no As are Cs. 4 No As are Bs. x is an A. Therefore, x is not B. 5 All As are Bs. All As are Cs. Therefore, all Bs are Cs. 6 All As are Bs. All As are Cs. Therefore, some Bs are Cs. 7 All As are Bs. Some As are Cs. Therefore, some Bs are Cs. 8 Some As are Bs. Some As are Cs. Therefore, some Cs are Bs. B. State whether the following are valid or invalid: 1 All As are Bs. All Bs are Cs. Therefore, all As are Cs. 2 All As are Bs. No Bs are Cs. Therefore, no As are Cs. 3 All As are Bs. Some Bs are Cs. Therefore, some As are Cs. 4 Some As are Bs. All Bs are Cs. Therefore, some As are Cs. 5 Some As are Bs. No Bs are Cs. Therefore, some As are not Cs. 6 No As are Bs. No Bs are Cs. Therefore, no As are Cs. 7 No As are Bs. Therefore, no Bs are As. 8 No As are Bs. x is an A. Therefore, x is not B. 9 All As are Bs. All As are Cs. Therefore, all Bs are Cs. 10 All As are Bs. All As are Cs. Therefore, some Bs are Cs. 8. SUMMATION: EVALUATING ARGUMENTS raised in section 2.1.3 ve covered a lot of ground in this chapter. Let's conclude by addressing the co in section 2.1. Since we don't generally know in advance whether an argum uld he trying to prove it valid or try