Bunuel
A history exam features 5 questions. 3 of the questions are multiple-choice with four options each. The other two questions are true or false. If Caroline selects one answer for every question, how many different ways can she answer the exam?
(A) 200
(B) 290
(C) 256
(D) 278
(E) 390
Take the task of completing the test and break it into
stages.
Stage 1: Answer the 1st multiple-choice question
Since there are 4 options from which to choose, we can complete stage 1 in
4 ways
Stage 2: Answer the 2nd multiple-choice question
Since there are 4 options from which to choose, we can complete this stage in
4 ways
Stage 3: Answer the 3rd multiple-choice question
We can complete this stage in
4 ways
Stage 4: Answer the 1st true/false question
There are 2 ways we can answer this question.
So, we can complete this stage in
2 ways
Stage 5: Answer the 2nd true/false question
We can complete this stage in
2 ways
By the Fundamental Counting Principle (FCP), we can complete all 5 stages (and thus complete the test) in [color=blue](4)(4)(4)(2)(2)/color] ways (= 256 ways)
Answer: C
Note: the FCP can be used to solve the MAJORITY of counting questions on the GMAT. So, be sure to learn it.
RELATED VIDEOS