# Homework Help: Topic to talk in math's fair

1. Dec 10, 2015

### Jakecp

1. The problem statement, all variables and given/known data
Which problem do you recommend us to talk in a science fair?

2. Relevant equations
no

3. The attempt at a solution
We have thought about paradoxes but our teacher told us that each person has a different point of view of something like the grand hotel paradox and we need to do a workshop , so , which topic can we do?

Last edited by a moderator: Dec 10, 2015
2. Dec 10, 2015

### Dr. Courtney

Are we talking about the math category in an ISEF-affiliated science fair or something else?

3. Dec 10, 2015

### Jakecp

It is an internal maths fair in our school . We are at 9th grade.

4. Dec 10, 2015

### haruspex

There are a lot of topics in probability and combinatorics that are readily understood (as a problem statement, at least) by most people.

Lots of pretty facts around Pascal's triangle (web search).

Finding the probability that if you cut a stick in two places randomly you can make a triangle (nice graphical solution).

Human underestimation of rare events: get a class to divide themselves into two groups; in one group each tosses a coin a hundred times and writes down the sequence; in the other group each pretends to toss the coin and writes down a random sequence of 100 results of their own invention. The invented sequences will hardly ever contain a run of five the same, whereas most of the real sequences will.

The 'birthdays' paradox. (This one is ok, there's no disagreement about its resolution amongst the experts.) Web search it if you don't know it. You could write some software to simulate it. A spreadsheet can do it.

The "Monty Hall" problem.

You wrote "talk", but I hope you have the opportunity for something more like a demonstration.

5. Dec 10, 2015

### Ray Vickson

You might think about issues of "exponential growth". The monetary effects of compound interest, for example, can lead to surprises, and yet is very relevant to everyday life. Population growth issues also may be of wide interest to your classmates.