When 335 is added to 5A7, the result is 8B2. 8B2 is divisible by 3. What is…
2023
When 335 is added to 5A7, the result is 8B2. 8B2 is divisible by 3. What is the largest possible value of A?
- A.
8
- B.
2
- C.
1
- D.
4
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Correct answer: D
Answer: 4
Explanation:
Units column: 5 + 7 = 12, so the units digit is 2 and there is a carry of 1 into the tens column.
Tens column: 3 + A + 1 = 4 + A. This equals the tens digit B. If 4 + A ≥ 10 there would be a carry into the hundreds, but the hundreds column must sum to 8 without an extra carry (see next point). Therefore 4 + A ≤ 9, so A ≤ 5 and B = 4 + A.
Hundreds column: 3 + 5 + (carry from tens). For the result to be 8, the carry from tens must be 0, confirming A ≤ 5.
Divisibility by 3: The number 8B2 is divisible by 3, so 8 + B + 2 = 10 + B must be divisible by 3. That gives B ≡ 2 (mod 3), so B can be 2, 5, or 8.
Combine B = 4 + A with the possible B values: 4 + A = 2 (impossible), 4 + A = 5 ⇒ A = 1, 4 + A = 8 ⇒ A = 4. Both A = 1 and A = 4 satisfy the constraints, and the largest possible A is 4.