View All num of num See all Photos Bloomberg L.P. This employer has taken extra steps to respond to reviews and provide job seekers with accurate company information, photos, and reviews. Interested for your company?Learn More. www.bloomberg.com Employer Engaged Overview Reviews Salaries Interviews Jobs Photos Benefits 1.3k Reviews 4.1k Salaries 2.2k Interviews 738 Jobs Follow Add Review or Salary Follow Add Review or Salary Interview Question Financial Software Developer Intern Interview(Student Candidate) New York, NY Bloomberg L.P. There are 20 floors in a building. If you're on an elevator and you're trying to get to the 20th floor, what is the probability that 4 people ahead of you click the 20th floor before you do? Assuming you click last. Tags: See more , See less 8 Answer Add Tags Answer Interview Answer 8 Answers ▲ 1 ▼ assume there is one button for each floor, so 20 buttons.a person can press any 1 button out of the 20, prob is 1/20.Since there are 4 people, so1/16000 ggg on May 30, 2012 ▲ 2 ▼ These are independent events so the chances of one person before you going to the 20th floor is 1/20. Since this happens 4 times before you the probability is 4*(1/20) or 1/5. Anna on Jun 3, 2012 ▲ 2 ▼ The above two are close, but wrong..There are 20 buttons, thus 20 choices, sure. But you are getting on at one of the floor. No body will press the button for the floor they get on..Thus, there is really only 19 choices.P = (1/19)^3 (Independent events mean (1/19)(1/19)(1/19)). hello on Jun 8, 2012 ▲ 3 ▼ 1/19 + 1/18 + 1/17 + 1/16 assuming that there were no repeated destinations. Ektor on Aug 8, 2012 ▲ 4 ▼ based on question:P(all 4 ahead of you want to get off on 20th fl) = (1/19)^4real life(all 4 want to get off on 20th fl, and one of them is the first person press the button to 20th fl, and that leave all others, including you, stay still):(1/19) * (1/4) Dekus on Sep 17, 2012 ▲ 1 ▼ about 20% is the right answer. I am surprised with some of the answers, they are all very small possibilities (some less than 1%). payman k on Oct 2, 2012 ▲ 0 ▼ I'm quite sure you are all wrong:The real probability is 1 - P(nobody pushes 20) = 1 - (18/19)^3 = 15% philly on Feb 16, 2014 ▲ 0 ▼ 1- (19/20)^4 S on Jan 7, 2015 Add Answers or Comments To comment on this, Sign In or Sign Up.