Question

Number 136 is added to 5B7 and the sum obtained is 7A3, where A and B are integers. It is given that 7A3 is exactly divisible by 3. The only possible value of B is

• A. 2
• B. 5
• C. 7
• D. 8

Answer 1

Answer:

D. 8

Solution: Concept: The divisibility rule of 3 states that a number is completely divisible by 3 if the sum of its digit is divisible by 3 or multiple of 3. Calculation: ⇒ 7 + A + 3 = 10 + A (Possible value of A is 2, 5, 8) ⇒ 136 + 5B7 = 7A3 (Possible value of B is 6, 7, 8, 9) ⇒ For A = 2, B = 8 ⇒ 7 + 2 + 3 = 12, (Which is divisible by 3 or multiple of 3) ⇒ The value of B = 8 ∴ The required result will be 8.