If you had two eggs, then you would have to start on the fiftieth floor. If it broke, then you would use the other egg and drop it from every floor from 1 to 50. The floor below the floor which it breaks on is the lowest floor which it can be dropped from without breaking.
If the first egg didn't break on the fiftieth floor, then you would drop the first egg from the 75th floor. If it does break, then you would drop the second egg from all the floors from 50 to 75. If the first egg didn't break on the 75th floor, then you try dropping it from the 83rd floor. If it does break then you test the second egg on all of the floors from 75 to 82.
If the first egg didn't break on the 83rd floor, then you test all the floors from the 83rd to the 100th.
Least amount of tries it can be with this solution is 30 times, the most is 50.