In the nth row of Pascal's Triangle where the first row is n, the arithmetic mean of the elements is 51.2 . What is the value of n?
OK. Just for fun !!!
51.2 x 10 =512
Log(512) / Log(2) =9th row !!.
The sum of any row = 2^n....starting with n = 0
And the number of elements in any row = n + 1
And the arithmetic mean is given by
Sum of the elements / their number
So we have
2^n / [ n + 1] = 51.2
2^n = 51.2 n + 51.2
We can solve this graphically here : https://www.desmos.com/calculator/xfcfgqc9rb
So...the solution is n = 9 = 9th row
And the sum of the elements in the 9th row = 512
And the aritmetic mean is  / [ 9 + 1 ] = 512 / 10 = 51.2