Question 1
"Jane is either a mountain hiker or a cross-country skier. She is not a mountain hiker. So she must be a cross-country skier" is
◦ modus ponens
◦ modus tollens
◦ contraposition
◦ disjunctive syllogism
◦ hypothetical syllogism
Question 2
"Sarah will take either calculus or organic chemistry next semester. Now since she cannot take calculus next semester, therefore she will be taking organic chemistry" is
◦ modus ponens
◦ modus tollens
◦ contraposition
◦ disjunctive syllogism
◦ hypothetical syllogism