When i posted my review about the movie “21,” i mentioned the Monty Hall problem presented in the movie. I intended to follow-up with the answer and forgot about it until today. Here’s a restatement of it::
You’re on the gameshow Let’s Make a Deal and are present with 3 doors. You’re told behind one is a brand new car, and behind the other two are goats. You choose a door, say Door A. Monty (who knows which door the car is behind) then reveals what is behind Door C - a goat. And he says to you, i’ll give you a chance to switch your choice to Door B. Do you switch doors?
Most people reason that there is an equal chance that the car is behind Door A and Door B, so there’s nothing to be gained by switching. Plus, there is a psychological warning in your head telling you that if Monty is suggesting that you switch, it must be bad for you to do so. So your gut instinct is to stick with your original choice.
Monty Hall problem
The correct answer is to switch doors. The car is twice as likely to be behind Door B than your original choice of Door A.
When you made your original selection, you had a 33.3% chance of getting it right. Which means a 66.6% chance of being wrong. That has not changed just because one of the doors has been opened. Your door still has a 33% chance of containing the car. But Door B is now 66.6% likely to contain the car. Switch!!
Pretty cool problem. If you don’t believe me - look it up.
21 is a the movie version of the book Bringing Down the House by Ben Mezrich. I read it last year and wrote a short review in this blog. It was an extremely fun and fast-paced book.
The movie was also fun. But it wasn’t as gripping. Or believable. Remember, the book was based on a true story. The movie changed some of the main plot lines to accomodate the “hollywood angles,” and it really lost some of its appeal. For example, the casino basement scenes with people getting beaten up?? That doesn’t happen. And they are simply not allowed to physically detain you - if they suspect you of counting cards, they can ask you to leave and that’s it.
I also found myself confused at the end. Did the team make a bunch of money on that last night or not? Was it all stolen, or had they properly accounted for variable change?
Also, it would have been more realistic to show them actually losing some big hands sometimes. Just because you count cards, doesn’t mean you’re not going to lose a lot of money sometimes. The edge they were working with was still pretty small - not big enough to guarantee you’ll win every hand. But i guess that would be too confusing for the general populace
All in all, it was an enjoyable movie, though. Kevin Spacy was awesome, though i would expect no less.
One other thing - i was intrigued to see the Monty Hall problem presented early in the movie. Here it is:
You’re on the gameshow Let’s Make a Deal and are present with 3 doors. You’re told behind one is a brand new car, and behind the other two are goats. You choose a door, say Door A. Monty (who knows which door the car is behind) then reveals what is behind Door C - a goat. And he says to you, i’ll give you a chance to switch your choice to Door B. Do you switch?It’s a fascinating problem if only because so many people get it wrong.
Last night was the program kickoff of the Woman & Math Mentoring program. I met the girls and their moms for the first time.
I was nervous! I wanted to convince the moms i was trustworthy enough for them to release their daughter into my care, as well as appear enthusiastic and cool to the girls so they will look forward to hanging out with me. I think i accomplished that.
First impressions: all three girls were absolutely beautiful. One was particularly introverted. They know each other already from school, which could be good or bad. If the two outgoing ones participate to the point of excluding the introvert, that might be bad. But, as an introverted person myself, i often enjoy kind of being an observer. So there will be a balance to strike to encourage participation but also letting it be okay to hang back a little.
All three are excelling in math right now, which is how they got chosen for this program. I asked them about their interests, which are wonderfully diverse. R wants to be a pediatrician. M wants to be a veterinarian. L wants to be… an actress. OK, not math-related AT ALL, but still cool. Of the many suggested ideas for field trips, to accomodate these girls’ interests, we’re going to go to Duke Children’s Center, NCSU Vet School and WRAL-TV.
I’m excited about seeing these places myself! I hope i can show them a good time while also be a positive influence and role model for them.
This is FREAKY.
Click this link to take the Right Brain vs Left Brain test.
I initially saw the dancer turning clockwise, so i guess that means my right brain is more dominant. Which surprises me, because i think the left-brain list describes me better. At first i didn’t understand how anyone would see it any other way. However, after staring for a bit and crossing my eyes, i saw her change direction and go counter-clockwise. Then she kept switching back and forth.
Totally weird, because once you see her, it’s hard to imagine her going the other way! Check it out.
On the off chance that someone might be interested, i’m going to post about a volunteer opportunity. The Women & Math Mentoring program asks professional women in a math, science or computer related field to mentor an 8th grade girl for the second half of the school year. Mentoring involves spending time with your 2 or 3 mentees about once a month, or a total of about 5 times.
It’s a pretty interesting program. This is my first year doing it, and i’m excited about it, but also not sure what i’m in for. They are still looking for some more mentors this year, so if you are interested, please check out their website.
http://www.womenandmathmentoring.org/
