Interview Question: One Lucky Dude

Sample Question #152 (probability brainteaser)

I give you a coin to toss. You toss it 100 times and get 100 heads. (Lucky you!) What’s the probability of getting heads again on your 101st toss?

Advertisements
This entry was posted in Sample Qs. Bookmark the permalink.

One Response to Interview Question: One Lucky Dude

  1. Brett says:

    ANSWER
     
    This is an excellent question that tests your ability to go beyond the textbook.  The textbook answer would be 50%, since that’s the odds of getting heads on any toss.  But if you got 100 heads in a row, that’s something wrong with the coin, e.g., it’s a loaded coin, so it’s likely when you toss again you’ll get another head.  If you think like this, the answer is 100%.  The "ideal" answer would be to mention both solutions. (But, please do not try to give "ideal" answers at an interview! Just give your best answer. Nobody can be perfect.)
     

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 )

Twitter picture

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

Facebook photo

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

Google+ photo

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

Connecting to %s