A multiple choice test has 10 questions with 3 choices each. How many ways are there to answer the test? What is the probability that two papers have the same answers?

Question

campbell_st · Answer

if you look at it this way 

Question      choices 
      1                 3
      2                 3
      3                 3
      4                 3
     etc               etc

you need to multiply the number of choices at each stage... 

but it can be simplified using powers