Wednesday, July 21, 2010

Pac Puzzler

How about a mental exercise to get you through the week? What's the solution to this Pac Puzzler?

You are a medical researcher and have a presentation in 24 hours for which 12 samples of placebo and 1 sample of vaccine has been prepared. Unfortunately your lab assistant forgot to label any of the samples and now can't remember which is which! On top of that you now only have four lab rats yet to receive the vaccine. You can administer the samples as you wish to the four rats but it will take 23 hours before you can test to see which received the vaccine.

How can you, without a doubt, find the 1 sample of vaccine out of the 13 total unlabeled samples with only four subjects to administer vaccinations to?! Time is ticking...


  1. Biggz, I know the answer. Who should I e-mail about my prize?

  2. Go ahead and post your answer here or on our Facebook Page but sorry, only pride and bragging rights for the correct answer. ;)

  3. You are making an assumption here, that a partial dose (say 1/3 - 1/5 of a sample), is sufficient to cause antibodies to be detected