Problem on probability

[admin]

The question is suppose i have n balls out of which 1 has different weight(maybe higher of lower than other balls).Also i have been provided with k which is the number of weighings.Now i have to answer that after k weighings are over what is the minimum probability required to guess the fake ball(ball with different weight) for any general n and k?

fo eg : some example cases
n k min probability
3 1 0.500000
3 2 1.000000
4 1 0.500000
1 5 1.000000