Bumblebee


problem: two trains enter a tunnel 200 miles long (yeah, its a big tunnel) travelling at 100 mph at the same time from opposite directions. as soon as they enter the tunnel a supersonic bee flying at 1000 mph starts from one train and heads toward the other one. as soon as it reaches the other one it turns around and heads back toward the first, going back and forth between the trains until the trains collide in a fiery explosion in the middle of the tunnel (the bee survives). how far did the bee travel?

Solution

solution: this puzzle falls pretty high on my aha scale. my first inclination when i heard it was to think “ok, so i just need to sum up the distances that the bee travels…” but then you quickly realize that its a difficult (not impossible) summation which the interviewer could hardly expect you to answer (unless i guess if you are looking for a job as a quant). “there must be a trick” you say. eh, sort of i guess, enough to say that this question is a stupid interview question.

the tunnel is 200 miles long. the trains meet in the middle travelling at 100 mph, so it takes them an hour to reach the middle. the bee is travelling 1000 mph for an hour (since its flying the whole time the trains are racing toward one another) – so basically the bee goes 1000 miles.

there is no process to explain, so this question can’t possibly teach you anything about the person. they either know it or they don’t and if they already knew it before you asked, you’re not going to be able to tell when they give you the answer. so don’t ask this question. and if someone asks you this question, just tell them you’ve already heard it before.

Explore posts in the same categories: INTERVIEW TIPS

Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

You can comment below, or link to this permanent URL from your own site.

3 Comments on “Bumblebee”

  1. Cara Carlis Says:

    Hello there, just required you to know I he added your website to my Google bookmarks due to your layout. But seriously, I think your web website has 1 in the freshest theme I??ve came across. It extremely helps make studying your website significantly easier.


  2. Thanx for that energy, sustain the great function Wonderful function, I’m likely to start off a tiny Web site Engine program perform employing your internet site I am hoping you get pleasure from running a blog with all the common BlogEngine.web.Thethoughts you express are genuinely amazing. Wish you may proper some a lot more posts.


  3. I couldn’t resist commenting


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s


%d bloggers like this: