For a number to be divisible by 11, the difference of the sum of numbers at even and odd places should be either 0 or a multiple of 11.
We assume the leftmost digit at position 1.
So, Sum of numbers at even places = 5 + 2 + 7 + 4 = 18
Sum of numbers at odd places = 2 + 8 + # + 2 = 12 + #
Now, to make the number divisible by 11, we equate the sums obtained in the above step.
18 = 12 + #
=> # = 6
Therefore, C (6) is the correct choice.
