A combination lock is to have 4 digits (using the numbers from 1 to 9 (ie No Zero)How many different combinations are there that have all di

Question

A combination lock is to have 4 digits (using the numbers from 1 to 9 (ie No Zero)How many different combinations are there that have all different numbers.

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Khánh Gia 5 years 2021-07-17T16:46:25+00:00 1 Answers 31 views 0

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  1. thaiduong
    0
    2021-07-17T16:47:48+00:00
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    Answer:

    3024

    Step-by-step explanation:

    You have to think of this in choices. You have 9 choices for the first lock (because there are 9 numbers). We would have 9 choices for the second lock, but we used one number for the previous one. So we would have 8 choices. We would continue with 7 choices for the third lock and 6 for the fourth.

    Multiplying this we get 9x8x7x6=3024

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