## Archive for January, 2011

### The road is the journey

Monday, January 31st, 2011

- A girl lives 500 metres from school.
- I knew a salesman once.
- She walks at a speed of 2 – 0.0025x m/s where x is the distance she has walked so far.
- The salesman never went to school.
- How long does she take to get to school?
- He was driven.
- x = 0 gives her starting speed: 2 m/s and x = 500 gives her speed when she reached school: 0.75 m/s.
- The salesman seldom went steady.
- Giving her average speed to 1.375 m/s  so she took  500/1.375 = 363.64 seconds.
- His wife did not approve.

### Quote

Monday, January 31st, 2011

Five out of four people have trouble with fractions. – Stephen Wright

### Reflections

Sunday, January 30th, 2011

On the art of making maths interesting: Vi Hart.

Ultimately, she hopes she can be a Martin Gardner for the Web 2.0 era.  “I want to be the ambassador of mathematics,” she said. More

### Playful thinking

Saturday, January 29th, 2011

MuMart is a computer language through which the user can create beautiful pictures, dynamic arts make game and control robots to create scenarios

I am taking a p2pu course on it at the moment. More information, and how to play, here.

### C is not a vitamin

Friday, January 28th, 2011

- I have 2011 numbers.
- Are they real?
- Of course they are real! Do you think I am dreaming?
- I just wanted to check.
- I subtract all these numbers from a number c.
- One at a time, or their sum?
- One at a time. Like x1 – c, x2 – c, …
- Doesn’t that take an awful long time?
- If a sum is negative I ignore the minus sign.
- Some kind of denial! Was you ever removed from your mother at birth?
- In other words, I calculate abs(x1 – c) + abs(x2 – c) + … + abs(x2011 – c).
- You never said you added them.
- Which c will give the smallest sum?
- I don’t know. The only c I have met that was a number was 2.
- That doesn’t help.
- By the way, why do you want to know?
- Is 0 + 0 = 1?

Problem source: Problem of the Week, Purdue University.

### Quote

Friday, January 28th, 2011

Skiing combines outdoor fun with knocking down trees with your face. – Dave Barry

### Stretching it

Thursday, January 27th, 2011

- Stop it once!
- I can’t stop it twice.
- I meant ‘at once.’
- What?
- Don’t play with that rubber band!
- I am not playing.
- It may be dangerous.
- It is.
- What is?
- Playing is.
- I thought you said you were not playing.
- I am trying to put myself in your shoes.
- Don’t change the subject. We were talking about rubber bands, not shoes.
- I am wondering.
- Stop it once. It is dangerous.
- If I stretch it, will there be points that won’t move?
- You are stretching it! Stop it once!

### Quote

Thursday, January 27th, 2011

The perfection of art is to conceal art. – Marcus Fabius Quintilian

### New York is neither A nor B

Wednesday, January 26th, 2011

Sometimes thnik again! gets apple emails from readers. A recent one.

I have to empty town A for apples and bring as many of them as I can to town B. B is 1000km away from A and I have only one truck to take the apples in. The truck can take a maximum of 1000 apples. Here is the problem: When I drive with apples I have to eat one of them every km I drive. It is called applemania and there is no cure for it as far as I know. How do I cure my applemania? How many apples can I bring to B?

Problem source: Math Puzzles. Creator: Vlad Mitlin.

### Quote

Wednesday, January 26th, 2011

It is the nature of all greatness not to be exact. – Edmund Burke