📢 Too many exams? Don’t know which one suits you best? Book Your Free Expert 👉 call Now!


    Question

    Find the smallest positive integer n such that 6n + 5 is

    divisible by 7.
    A 5 Correct Answer Incorrect Answer
    B 8 Correct Answer Incorrect Answer
    C 11 Correct Answer Incorrect Answer
    D 17 Correct Answer Incorrect Answer

    Solution

    ATQ,

    6n + 5 ≡ 0 mod7 → 6n ≡ 2 → n ≡ 2×6⁻¹ mod7 → 6⁻¹ ≡ 6 (since 6×6 ≡ 1 mod7) → n ≡ 12 ≡ 5 mod7 → n = 5.

    Practice Next
    ask-question