Subscription

Books
Shop
About

Friday, September 30, 2011

Should I say yes or should I say no?

Without mathematics, how would I know how to make good decisions?
Quick example: I like two jobs equally, one offers $1 a month and the other $1.20 per month. Which should I take (assuming they're the same in every other way?) Ok, that was too easy.

How about this, I could pay N100 to enter a lottery that pays out N1000 to one winner. Should I do it?
In maths actually, when things are uncertain, you think of "expected values." In this example, if you're spending N100, what do you EXPECT to receive? Mathematically, you multiply the amount by the PROBABILITY to get the EXPECTED AMOUNT.

Answers: If I have a 50-50 chance of winning (like if only two people entered the lottery) then yes, go for it!  On the other hand, if I have a 1 in 100 chance of winning, then I should just keep my money and wait for a better opportunity.

Why? In the first case, the expected payoff is big, you expect to get N1000 * 50% = N500 for spending only N100
but
in the second case, the payoff (expected) is negative since you expect to get N1000 * 1/100 = N10 only, which is less than the N100 you spent.

The gray area: sometimes a positive payoff may not be worth it (but that's a question of psychology or other factors, which you can learn to include in your calculations as well).  If you think about it, this DECISION THEORY stuff can help you make many different kinds of decisions in a way that is rational.

This is the JULY 2011 blog post - I'm still playing catch-up

Wednesday, September 7, 2011

Khan Academy makes math-lovers



When you visit KhanAcademy.org, go straight to PRACTICE. Within one hour, math has become a fun, competitive sport. At least that's what my young cousin experienced; for days, he kept going back to do more math drills and score more points and badges.

So don't hate math, just play Khan.

For older folk, Khan trains in Contemporary Finance topics (example: Systemic Risk), Aptitude tests like SAT and GMAT, Entrance exams like IIT JEE (India), standard curricula like Singapore and some US states, a bit of the sciences - physics, chemistry...all for the price of your video-capable internet connection.

JUNE 2011 POST (to make up for being MIA ;)

My Other Blogs

  • Henna - * more tattoo inspiration * ... Mehndi (India) Laali (Nigeria) Henna (Middle East) Want fine African Literature? Nigerian Lifestyle A-Z at REALbubbl...
    1 day ago
  • It's so nice to have internet - 30 Gigs a month. 💃💃 I can watch lots of videos (at low/medium resolution), sneak in some downloads, and not even have to worry about wasting minutes of ...
    3 days ago
  • Weekend MUSIC: #GoingHome - Home by Chris Daughtry and Eyo by Asa NEWSBUKA for all the burning topics in Nigerian politics and society. GeT FREE EmAiL UpDaTeS"
    4 days ago
  • We are Goal Number One - Sustainable Development Goals Goal 1. End poverty in all its forms everywhere Yes, We Can. Get UpNaira email updates. Order Big Girl and Big Boy. Re...
    1 week ago
  • All Sorts Of Math Jobs - [image: http://siam.org/careers/thinking/pdf/brochure.pdf] Enjoy and Share Advertisement: Read my books.
    5 weeks ago

About Me

Followers