The number of 4 digits number which do not contain 4 different digit is (a) 2432 (b) 3616 (c) 4210 (d) 4464

Short Answer

Expert verified
The number of 4-digit numbers which do not contain 4 different digits is 4464.

Step by step solution

01

Calculate Total 4-Digit Numbers

Calculate the total number of 4-digit numbers. Since the first digit can be any of the 9 numbers 1 to 9 and the remaining 3 digits can be any of the 10 numbers 0 to 9, there are 9 × 10 × 10 × 10 = 9000 possible 4-digit numbers.
02

Calculate 4-Digit Numbers with 4 Different Digits

For a 4-digit number with all 4 digits different, the first digit can be any of the 9 numbers 1 to 9. For the second digit, there are 9 remaining options (0 to 9, excluding the first digit). The third digit can be any of the 8 remaining options, and the fourth digit can be any of the 7 remaining options. So, there are 9 × 9 × 8 × 7 = 4536 4-digit numbers with 4 different digits.
03

Calculate 4-Digit Numbers with at Least One Repeated Digit

Since we have already calculated the total number of 4-digit numbers and the number of 4-digit numbers with 4 different digits, we can now find the number of 4-digit numbers with at least one repeated digit by subtracting these two values: 9000 - 4536 = 4464. So, there are 4464 4-digit numbers with at least one repeated digit.
04

Choose the Correct Answer

Comparing this result with the given answer choices, we find that the correct answer is (d) 4464.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Study anywhere. Anytime. Across all devices.

Sign-up for free