View All num of num See all Photos Microsoft www.microsoft.com Engaged Employer Overview Reviews Salaries Interviews Jobs Photos Benefits 10k Reviews 33k Salaries 4.3k Interviews 5.2k Jobs Follow Add Interview Follow Add Interview Interview Question Software Development Engineer In Test Intern Interview(Student Candidate) Redmond, WA Microsoft You have a building with 100 stories. You also have two glass balls. You can drop the glass balls as many times as you want before they break. How can you find the floor at which they start breaking with the fewest number of drops? Tags: brain teaser See more , See less 8 Answer Add Tags Answer Interview Answer 3 Answers ▲ 0 ▼ Not truly a brain teaser because the answer is mathematical. Interview Candidate on Apr 21, 2012 ▲ 1 ▼ If you have N stories, you use the first glass ball to increment by sqrt(N) stories. Once that ball breaks, you use your second to go to the level of sqrt(N) below where it broke, and increment floor by floor. You know it must break somewhere in that group of sqrt(N) stories. I believe this method gets you a runtime of O(n^0.5). Alex on May 2, 2012 ▲ 1 ▼ search for "two egg problem". its a minimization of maximum regret problemhttp://www.datagenetics.com/blog/july22012/index.html moataz on Oct 4, 2012 Interviews > Software Development Engineer In Test Intern > Microsoft Add Answers or Comments To comment on this, Sign In or Sign Up.