If the mean deviation of the numbers 1, 1 + d, 1 + 2d, ... , 1 + 100d from their mean is 255, then the d is equal to

- 10
- 10.1
- 20
- 20.2

**Answer**

| (x - mean)/n | = 255

Mean = (1 + 1 + 2d + 1 + 3d + ... +1+ 100d)/101

= 101 + d(100x101/2)/101

= 1 + (50x101d)/101

= 1+ 50d

|x - mean| = 255 x 101

**The correct option is B.**