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?
Aptitude
Permutation and Combination
Difficulty: Easy
Choose an option
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A20
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B24
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C18
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D30
Answer
Correct Answer: 20
Explanation
Problem restatementForm 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/ApproachFix 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/AlternativeListing logic shows structure H–T–5; choices reduce sequentially without repetition.
Final Answer20