If the number 556743A57B is divisible by 8 and 9, then find 2A – B.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 6.
The number 556743A57B will be divisible by 8 if 57B is divisible by 8.
⇒ 57B is divisible by 8 if B is 6. (∴ B = 6)
The number 556743A57B would be divisible by 9, if the sum of the digits is divisible by 9.
⇒ sum of digits = 5 + 5 + 6 + 7 + 4 + 3 + A + 5 + 7 + 6 = 48 + A
⇒ If A = 6, sum of digits is divisible by 9. (∴ A = 6)
Value of expression 2A - B = (2 × 6) - 6 = 6