[This is a lesson excerpt from our online course, for which we invite you to enroll.]


Sufficient Assumption questions are like Inference Must be True (MBT) questions, in reverse.

In MBT questions, you’re given all the premises and asked to find the conclusion that would make for a valid argument. Here, you’re given the conclusion and all the premises (minus one). You’re asked to supply that missing premise which will make the argument valid. So really, they can easily turn any MBT question into a SA question by switching out the right answer choice for a premise in the stimulus. Or vice versa.

Idea bridging, as we will revisit in Necessary Assumptions questions, has a prominent role to play here. You have to connect the ideas in a very specific way. You have to build a conditional bridge from the premises to the conclusion. About half the SA questions says something like here’s my premise: “X” and here’s my conclusion: “Y.” You have to supply the missing premise: “If X, then Y.” With this missing premise, the argument receives all the additional support it could ever hope for and achieves that rarified status of validity.

The other type of SA questions has conditional or intersection statements already in the premises or conclusion. Stimulus might say something like “A –> B” therefore, “A –> C.” You’re being asked to supply the missing premise “B –> C.”

Remember the valid argument forms? Like the MBT questions, the SA questions also make use of those. Now’s a good time to review. Also like the MBT questions, if you’re aiming for 170+, these questions have to be freebies for you.


  • The critic’s conclusion follows logically if which one of the following is assumed?
  • Which one of the following, if assumed, allows the conclusion of the therapist’s argument to be properly inferred?
  • The argument’s conclusion is properly drawn if which one of the following is assumed?
  • The conclusion above follows logically if which one of the following is assumed?

SA questions also make heavy use of logic. Practice mapping out the logic in the stimulus.