Find the two-digit numbers A and B such that the number 65AB0 is divisible by…

2025

Find the two-digit numbers A and B such that the number 65AB0 is divisible by 66.

  1. A.

    15, 16

  2. B.

    16, 16

  3. C.

    17, 17

  4. D.

    17, 18

Attempted by 5 students.

Show answer & explanation

Correct answer: C

Step-by-Step Solution

  1. Analyze the Divisor: To be divisible by 66, a number must be divisible by its co-prime factors, which are 2, 3, and 11.

  2. Apply Divisibility Rules:

    • Divisibility by 2: The number 65AB0 ends in 0, so it is even and satisfies the rule for 2.

    • Divisibility by 3: The sum of the digits must be divisible by 3.

    • Divisibility by 11: The alternating sum of the digits must be divisible by 11.

  3. Test Option C (A=17, B=17): The number becomes 6517170.

    • Sum of digits: 6 + 5 + 1 + 7 + 1 + 7 + 0 = 27. Since 27 is divisible by 3, the number satisfies the divisibility rule for 3.

    • Alternating sum: (6 + 1 + 1 + 0) - (5 + 7 + 7) = 8 - 19 = -11. Since -11 is divisible by 11, the number satisfies the divisibility rule for 11.

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