If the five - digit number 672 xy is divisible by 3, 7 and 11, then what is the value of (6x + 5y)?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 17
672xy is divisible by 3, 7, and 11
Sum of all digit = 6 + 7 + 2 + x + y = 15 + x + y
⇒ x + y = 0 or 3
⇒ x + y = 3 --(i)
To check the divisibility rule of 11
⇒ 8 + y - 7 - x = 0
⇒ x- y = 1 --(ii)
From (i) and (ii), we get x = 2 and y = 1
So, 6x + 5y = 12 + 5 = 17