Which among the given options is completely divisible by 45?

2025

Which among the given options is completely divisible by 45?

  1. A.

    202860

  2. B.

    234567

  3. C.

    3456778

  4. D.

    998765

Attempted by 3 students.

Show answer & explanation

Correct answer: A

To determine if a number is divisible by 45, we must check if it is divisible by the coprime factors of 45, which are 5 and 9.

Divisibility Rules

  • Divisibility by 5: The last digit must be 0 or 5.

  • Divisibility by 9: The sum of all the digits must be divisible by 9.

Step-by-Step Analysis of Options

  • Option A: 202860

    • Rule for 5: Ends in 0, so it is divisible by 5.

    • Rule for 9: Sum of digits = 2 + 0 + 2 + 8 + 6 + 0 = 18. Since 18 is divisible by 9, it is divisible by 9.

    • Conclusion: Divisible by both 5 and 9, so it is divisible by 45.

  • Option B: 234567

    • Rule for 5: Ends in 7, so it is not divisible by 5.

  • Option C: 3456778

    • Rule for 5: Ends in 8, so it is not divisible by 5.

  • Option D: 998765

    • Rule for 5: Ends in 5, so it is divisible by 5.

    • Rule for 9: Sum of digits = 9 + 9 + 8 + 7 + 6 + 5 = 44. Since 44 is not divisible by 9, it is not divisible by 9.

Summary

  • Option A is the only number that satisfies both conditions (ends in 0 and has a digit sum divisible by 9).

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