A random 9-digit numeric passcode is generated. If the first digit cannot be 0, 2, or 8, and the last digit cannot be a prime number, how many unique codes can be formed?

Correct answer marked below

A

180,000,000

B

240,000,000

C

300,000,000

D

360,000,000

420,000,000

Correct

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T

TuckerSep 7, 2024

got this wrong on my practice

S

SaurabhFeb 20, 2024

Thank you very much!

What this question tests

Whether you can count arrangements and selections correctly — permutations vs. combinations.

Overcounting: treating a selection as ordered when order does not matter, or forgetting to divide by duplicates.

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