View All num of num See all Photos Google www.google.com Engaged Employer Overview Reviews Salaries Interviews Jobs Photos Benefits 3.2k Reviews 11k Salaries 3.9k Interviews Follow Add Review or Salary Follow Add Review or Salary Interview Question Associate Product Manager Interview Mountain View, CA Google How many ping pong balls fit in a school bus? Tags: See more , See less 8 Answer Add Tags Answer Interview Answer 2 Answers ▲ 0 ▼ There's a few things I would clarify with the interviewer before starting but I'll spare you for now.Let's start with the size of the balls, that we assume will have a radius of 2cm.To account for the gap between balls when filling a space, we will also assume that the balls take up the space of a 4cm x 4cm cube (16cm3). At the end we will also add an extra ball for every 4 balls to account for the gap neglected in assuming a cube.To keep things simple, we assume we have nothing inside (no seats, etc). In guesstimating the dimensions of the bus we'll say each seat would be 3.5ft long while the center aisle is 1.5ft for a total width of 8.5ft. We'll also guess that a bus is about 40ft long and 8ft tall. This brings our net volume to: 2,720ft3.1ft ~ 30.5cm2,720ft3 ~ 77,021,823cm377,021,823cm3 / 16cm3 ~ 4,813,864 ballsAccounting for gap: 4,813,864 / 4 ~ 1,203,466 ballsNet total: 4,813,864 + 1,203,466 = 6,017,330 balls Luca on Jul 31, 2013 ▲ 3 ▼ Another ridiculously detailed answer can be found at > http://www.nab.bz/bus-explanation.pdfThis is not my work, just found it while preparing. Luca on Jul 31, 2013 Interviews > Associate Product Manager > Google Add Answers or Comments To comment on this, Sign In or Sign Up.