Correct Answer - Option 4 : 2

**Given:**

Number = 179x091y

**Concept used:**

1) If the last three digits of a number are divisible by 8, then the number is completely divisible by 8

2) If the difference of the sum of alternative digits of a number is divisible by 11, then that number is divisible by 11 completely.

3) If any number is completely divisible by 88 then the number is also completely divisible by 8 and 11

**Calculation:**

Given number is completely divisible by 88 then it is also divisible by 11 and 8

When the number is divisible by 8 then,

91y is divisible by 8 when y = 2 ----(1)

When the number is divisible by 11 then,

(7 + x + 9 + y) – (1 + 9 + 0 + 1)

⇒ 16 + x + y – 11

⇒ x + y + 5

⇒ x + 2 + 5 ----(From eq (1))

⇒ x + 7

Now, (x + 7) is divisible by 11 when x = 4 then,

x – y = 4 – 2 = 2

**∴ The required difference is 2 **