Out-of-the-Box Thinking Questions

[ This page available at:  bit.ly/csthink ]

Innovation in Computer Science often comes through Out of the Box Thinking.  Form a group of 3-4, and see if you can figure out an answer to each of the problems shown below.

1. You have two eggs of identical size and weight.  One has been hard-boiled.  How can you tell which is which without breaking them?

2. There are eleven birds perched on a fence. A farmer aims his rifle and shoots one.  How many birds are left?

3. Why are manhole covers round?

4. Someone falls out of a 25 story building and hits the sidewalk without anything to slow them down, but lives.  How did they survive the fall?

5. You are driving in your car on a stormy night and drive by a bus stop where you see three people waiting for a bus:

An elderly lady that looks as if she is about to die, 

An old trusted friend, and

The perfect partner you have always dreamed of. 

You know your car can only seat one additional person.  To whom do you offer a ride?

6. You have a five gallon bucket and a 3 gallon bucket.  There are no markings on the buckets.  How can you get exactly 4 gallons in the 5 gallon bucket?

7. How can you connect the 9 dots below with just 4 straight drawn lines, without removing your pencil from the paper?
                         .     .     .  
                         .     .     .  
                         .     .     .   

8. You have eight identical-looking baseballs all of the same size. Seven weigh the same, and one of them weighs slightly more, although it is so slight you can’t tell by hand. How can you find the baseball that is heavier by using a balance scale to compare weights, using it only twice?         

9. You are in the lunchroom with 5 other employees, and are soon to go in to talk to your boss for your salary review.  You aren’t sure whether or not to ask for a raise.  If you already have the highest salary you will get fired, but otherwise you will get a raise.

10.  How can you find the average salary of everyone in the lunchroom without anyone having to divulge her or his actual salary to anyone else?  You have paper and pencil available. Assume everyone recognizes everyone else’s handwriting.

11. While walking your dog at the park, how could you cross each of these bridges exactly once on your walk, before stopping to rest? (From http://simonkneebone.com/2011/11/29/konigsberg-bridge-puzzle/ )