Difficulty: Medium
Correct Answer: 127
Explanation:
Introduction / Context:
When a number d divides two numbers leaving remainders r1 and r2, it divides the corresponding differences (N1 - r1) and (N2 - r2) exactly. The required greatest divisor is then gcd(N1 - r1, N2 - r2).
Given Data / Assumptions:
Concept / Approach:
Compute A = 1657 - 6 and B = 2037 - 5, then find gcd(A, B) using the Euclidean algorithm.
Step-by-Step Solution:
A = 1651, B = 2032.B - A = 381.Compute gcd(1651, 2032): gcd(1651, 381) since 2032 - 1651 = 381.1651 = 381 * 4 + 127.381 = 127 * 3 + 0 ⇒ gcd = 127.
Verification / Alternative check:
Check divisibility: 1651 ÷ 127 = 13; 2032 ÷ 127 = 16; hence 127 divides both differences and works.
Why Other Options Are Wrong:
235, 260, 305, 381 do not evenly divide both 1651 and 2032, or are not the greatest common divisor.
Common Pitfalls:
Taking gcd of 1657 and 2037 directly (ignoring remainders), or subtracting the wrong remainders.
Final Answer:
127
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