# Puzzle of the Week: The Balloons Know — Solution

Last week, we needed help determining which of our witnesses was involved in a bank robbery. We got it! Congratulations to Shane for having his correct answer randomly chosen from all of the correct answers we received. Shane will receive a \$50 gift certificate from ThinkGeek! The rest of you can read to the end of this post for a code to use to get \$10 off a \$40 or more purchase.

### Puzzle

After a string of robberies, several (female) witnesses were interviewed. We need you to tell us which of the witnesses was working with the robbers.

Alice: I work at the Balloon Factory. Three people came in at 4:00 PM, asked for three balloons to be filled with helium, then left without paying. Two of those three people are on your wanted list. I didn’t get a good look at the third person.

Barb: I saw three people leave the Balloon Factory with a bunch of balloons, get into an SUV and drive off toward the bank. I saw the faces of the same two people Alice saw. I did not see the face of the third person, he or she was holding the balloons in the back seat as they drove by and I didn’t see the face. They were driving slowly like the rest of traffic.

Christine: I was at the bank when they robbed it. I only saw the same two people Alice saw; the third person was using the balloons to block the security camera.

Daphne: I saw the faces of all three people; the third person is Alice. I could see her face as she drove the get-away car. They put the balloons in the middle row of the back seat and when she drove past me accelerating like crazy, the balloons were pushed back into the rear seat and her face was perfectly clear. I was walking toward the bank as they drove past me.

The police have confirmed that the single security camera (this is a small-town bank) was blocked by balloons. There are matching tire-burn marks in the bank parking lot and on the street nearby. Statements from other witnesses seem to corroborate Daphne’s assertion that the third suspect was female. They also confirmed that the suspects drove an SUV and burned rubber leaving the bank.

One of these people is not telling the truth and is the third person involved in the bank robbery. Who is it?

### Solution

Daphne’s story doesn’t make sense. She said that the helium balloons were forced to the back of the vehicle when the driver accelerated. That’s not what helium balloons do in a car. When accelerating, things with more mass (air) would be pushed to the back of the car by inertia which would push lighter stuff (heluim) to the front of the car.

Here are some good explanations (as always, it seems there is nothing that cannot be answered with a little googling).

To get \$10 off your next \$40 or more purchase from ThinkGeek, use the code: GEEKPUZZLER.
Come back on Monday for a new puzzle!