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How many 3-digit numbers can be formed from the digits 2, 3, 5, 6, 7, 9 that are divisible by 5 with no repeated digits?

Difficulty: Easy

Correct Answer: 20

Explanation:

Problem restatement
Form 3-digit numbers from {2, 3, 5, 6, 7, 9} that are divisible by 5 and have no repeated digits.


Given data

  • Available digits: 2, 3, 5, 6, 7, 9.
  • Divisibility by 5 ⇒ last digit must be 5 (0 is not available).
  • No repetition allowed.

Concept/Approach
Fix the units digit as 5, then choose hundreds and tens from remaining distinct digits.


Step-by-step calculation
Units digit = 5 (1 way) Hundreds digit = choose from {2, 3, 6, 7, 9} ⇒ 5 ways Tens digit = choose from remaining 4 digits ⇒ 4 ways Total numbers = 1 × 5 × 4 = 20


Verification/Alternative
Listing logic shows structure H–T–5; choices reduce sequentially without repetition.


Final Answer
20

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