If the 10 - digit number 96530y15x8 is divisible by 72, then what is the value of (3x - 7y) for the maximum value of x?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 4.
Using Divisibility rule of 8, –
5x8 is completely divisible by 8 if x is 6. (∴ x = 6)
Similarly using divisibility rule of 9, –
9 + 6 + 5 + 3 + 0 + y + 1 + 5 + 6 + 8 = 43 + y
The number is perfectly divisible if y = 2 (∴ y = 2)
Value of 3x – 7y = 3 × 6 – 7 × 2 = 18 – 14 = 4
The value of 3x – 7y is 4.