A person has inherited a surplus grain mountain of 30000 tonnes held in a warehouse.each year 5% of the grain is eaten by mice.The person is obliged to addN tonneseach year.find the maximum of N such that mountain will decrease in size.

This is what I have understood the problem.

Initial amount=30000 Tonnes

Each year 5% loss implies remaining amount is 95%.

N tonnes is added each yer.

So I can form the recurrence relation as x_n=0.95 x_n-1+N

But how an I find the maximum of N?