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The digits 0, 1, 2, 3, and 4 are to be used in a four-digit ID card. a) how many different cards are possible? b) If repetition are permitted? c) If repetition are not permitted?​

User Jacksonsox
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2 Answers

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29 votes

Answer:

a) Varies on b and c

b) 625 combinations

c) 120 combinations

Explanation:

a) How many different cards are possible?

Leads to (b and (c

It depends on if repetition are permitted.

in a 4 digit numerical combination, you were given 5 numbers.

b) If repetition are permitted:

you can put any of the given 5 digits to the 1st, 2nd, 3rd, and 4th position.

Each digits would have 5 turns.

This means that you will have 5 x 5 x 5 x 5 If there is repetition,

which is 5⁴ is 625 possible combinations.

c) repetition are not permitted:

This would mean that you have;

5 turns for the first digit,

4 turns for the second digit,

3 turns for the third digit,

2 turns for the fourth digit.

which means you have 5 x 4 x 3 x 2 possible solutions.

5 x 4 x 3 x 2 = 120

There will be 120 possible combinations in total if there's no repetitions.

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Hope this helped!

User Alexander Blyth
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9 votes
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If repetition not permitted 5*4*3*2*1 if it is 5*5*5*5*5
User Tycho Pandelaar
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2.8k points