JEE Main 2016 · 9 Apr · Shift 1 · Mathematics Q86

MathematicsSingle correct+4 / -1Question 86 of 90

If the mean deviation of the numbers 1, 1 + d, ..., 1 + 100d from their mean is 255, then a value of d is :

10.1

20.2

5.05

Answer and worked solution

Official answer: A

The mean is $1+50d$ , and the mean deviation is $\frac{|d|}{101}\sum_{k=0}^{100}|k-50|=\frac{2550|d|}{101}=255$ , so $|d|=10.1$ .

JEE Main 2016 · 9 Apr · Shift 1, Mathematics question 86