Chapter 6: Conditional Reasoning

Question 1

if sufficient, then _

Answer 1

necessary

Question 2

contrapositive of sufficient

Answer 2

• negative Both and flip arrow
  (i.e. If A -> B = ~B->~A) (~A->B= ~B->A)

Question 3

conditional indicators (sufficient)

Answer 3

1. if
2. when
3. whenever
4. every
5. all
6. any
7. people who
8. in order to

Question 4

conditional indicators (necessary)

Answer 4

1. then
2. only
3. only if
4. must
5. required
6. unless
7. except
8. until
9. without

Question 5

the unless equation

Answer 5

• works for unless, except, with, without
  1. whatever term modified by unless is the necessary condition
  2. the other term is negated and is sufficient

Question 6

either/or statements

Answer 6

• in the LSAT, either/or is at least one BUT maybe both
  ex: either Jack or Sam will go (~J->S)(~S->J)(J->~S)(S->~J)

if they say “but not both,” then you knock out the second half

Question 7

contrapositives with multiple conditions

Answer 7

*if you are taking a contrapositive, switch And->Or and vice versa

i.e. To graduate, you must be smart and resourceful. (Grad-> smart AND resourceful. if ~smart or ~resourceful->~grad)