Difficulty: Easy
Correct Answer: 122
Explanation:
Introduction / Context:Numbers leaving the same remainder upon division by several divisors are handled using the Least Common Multiple (LCM). The pattern is N ≡ r (mod each divisor), hence N − r is a common multiple of all divisors.
Given Data / Assumptions:
Concept / Approach:Compute LCM of the divisors, then set N = LCM + r for the least positive solution. In general, all solutions are N = LCM * k + r, k ≥ 1 integer, but k = 1 gives the smallest positive answer beyond r itself (which will not satisfy divisibility here).
Step-by-Step Solution:
Prime factors: 12 = 2^2 * 3; 15 = 3 * 5; 20 = 2^2 * 5; 24 = 2^3 * 3.LCM = 2^3 * 3 * 5 = 120.Least N = 120 + 2 = 122.Verification / Alternative check:
122 ÷ 12 leaves 2; 122 ÷ 15 leaves 2; similarly for 20 and 24, remainder is 2 each time.Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:
122
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