Question

In 87659_21 what is the least number that can be filled in blank to make the number divisible by 11.
1. 7
2. 1
3. 3
4. 2

Answer 1

Correct Answer - Option 2 : 1

Given:

Number = 87659_21

Number divisible by 11.

Concept used:

Divisibility rule of 11: If the sum of digits at odd and even places are equal or differ by a number divisible by 11, then the number is also divisible by 11.

Calculations:

Let the missing number be x.

The sum of digits at odd and even places of 87659x21

Odd places = 8 + 6 + 9 + 2

Even places = 7 + 5 + x + 1

Odd places - Even places = 0 or 11

⇒ 25 - (x + 13) = 0

⇒ x = 25 – 13

⇒ x = 12

or

25 - (x + 13) = 11

⇒ 25 - x - 13 = 11

⇒ x = 12 - 11

⇒ x = 1

∴ The value of x is 1.