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Math Help - permutations question. "basic"

  1. #1
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    permutations question. "basic"

    there are a few questions like this and Im having trouble with them.

    a multiple choice test has 5 questions, with 4 possible answers per question, how many ways are there to complete the test?

    I havent done any of this type of math in a long time so Im stumped.
    I know it has something to do with multiplying the number of questions by the number of possible solutions per question?


    I aslo did one other question but the book is giving me the wrong answer but I could swear I did it right.
    it is.
    how many 2 digit whole numbers can me made using the numbers 1,2,3,4,5,6,7,8 with no repetitions.


    I could do the one with repatriations.
    =8x4=32

    but without repetitions I get an incorrect answer.
    I do 8x3=24, but the answer is 28
    I do that because there are 8 possible digits for the ten's and 4 possible for the one's, and I thought you subtracted one from the one's so there are no repetitions? I understand If I took 1 away from 8 and multiplied it by 4 its 28 but why?


    thanks
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  2. #2
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    1. 4^5

    2. (8)(7)
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  3. #3
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    Quote Originally Posted by Plato View Post
    1. 4^5

    2. (8)(7)
    shortest answer ever haha. I pretty much get it though thanks.
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