It can be solve in a number of ways.kvcpk wrote:Thanks for all your replies guys..
I wanted to confirm the rule that I was using.. I am answered now..
Thank you!!
Method 1
y = 25x - x^2 = x(25-x)
Sum of x and 25-x is constant. It will attain a max value at x = 25-x mpliy x = 12.5
Method 2
First derivative = 0 as gmatmachoman did it.
Method 3
y = 25x - x^2 = (25/2)^2 - (25/2 - x)^2
y to be max, (25/2 - x)^2 should be zero; imply x = 12.5
It is dependent on the comfort level of individuals.