A number gives quotient 269 and remainder 0 when divided by 68. When the same number is divided by 67, what is the remainder?
Aptitude
Numbers
Difficulty: Easy
Choose an option
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A0
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B1
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C2
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D3
Answer
Correct Answer: 1
Explanation
Given data
- N = 68 × 269 (since remainder is 0 on division by 68).
- Find N mod 67.
Concept / Approach
- Use modular arithmetic: (ab) mod m = [(a mod m)(b mod m)] mod m.
- Since 68 ≡ 1 (mod 67), N ≡ 1 × (269 mod 67) (mod 67).
Step-by-step calculation
269 = 67 × 4 + 1 ⇒ 269 mod 67 = 1Therefore, N mod 67 = 1
Verification
N = 68 × 269 = 18,292; 18,292 ÷ 67 = 272 remainder 1.
Common pitfalls
- Reducing both factors needlessly; recognizing 68 ≡ 1 (mod 67) simplifies immediately.
Final Answer
1