Question

    Determine the smallest 4-digit number that, when divided

    by 15, 24, and 30, leaves a remainder of 5 each time.
    A 1265 Correct Answer Incorrect Answer
    B 1545 Correct Answer Incorrect Answer
    C 1085 Correct Answer Incorrect Answer
    D 1235 Correct Answer Incorrect Answer

    Solution

    Prime factorization of 15 = 3 1  X 5 1 Prime factorization of 24 = 2 3  X 3 1 Prime factorization of 30 = 2 1  X 3 1  X 5 1 LCM of (15, 24, and 30) = 2 3  X 3 1  X 5 1  = 8 X 3 X 5 = 120 Least 4-digit number divisible by 120 = 1,080 So, required number = 1080 + 5 = 1,085

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