Explanation
1. Find the Mean (xˉ)
The given numbers are in an Arithmetic Progression: a=1, common difference =d, and number of terms n=101 (since the sequence goes from 0d to 100d).
For an AP, the mean is the average of the first and last terms:
xˉ=21+(1+100d)=22+100d=1+50d
2. Calculate the Mean Deviation (M.D.)
The formula for Mean Deviation from the mean is:
Substitute xi=1+id and xˉ=1+50d:
∣xi−xˉ∣=∣(1+id)−(1+50d)∣=∣(i−50)d∣
Assuming d > 0, the sum becomes:
i=0∑100∣i−50∣d=d[∣0−50∣+∣1−50∣+⋯+∣50−50∣+⋯+∣100−50∣]
Sum=d[50+49+⋯+1+0+1+⋯+49+50]
This consists of two identical series of 1 to 50:
3. Solve for d
Given M.D.=255 and n=101:
Multiply by 101:
Divide by 255:
Correct Option: (b)