Roulette is a popular randomized game at most casinos
このレッスンでは、可能性、確率と、あることがそれらにいかに影響するのか、しないのか、など考えてみましょう。
A man was playing roulette. Red had come up six times in a row. He knew that it was very improbable for red to come up seven times in a row, therefore black was almost certain to come up next. He'd been having a bad night and it was too late to turn back now, so he took an educated guess, and put the rest of his gambling money on black.
Is this a good bet? Why?
Ask: Is his premise correct? (How probable is it for red to come up seven times in a row? Not very. It's 50% x 50% x 50% x 50% x 50% x 50% x 50% = about 0.8% How probable is it for red to come up on the seventh spin? 50%). While the overall odds of a 'big run' happening may be low, each spin of the wheel is itself entirely independent from the last. That means that every spin, there is a 50/50 chance of red or black regardless of what came up before.
Unless of course, the casino is breaking the law and the roulette table is rigged.
In this lesson, we'll discuss odds
To discuss odds and probability, we can use phrases like: "Odds are it will..." or "Chances are it will..."
Can you think of any more words or phrases?
Discuss the probability of the following:
- How's the weather going to be next week?
- If you follow a sports team, what are the chances of them winning the next match?
- What are the odds of the yen increasing in value next year?
On a different but related topic, let's discuss the fallacy of sunk costs. A common idiom for this is "Throwing good money after bad." Can you think of any examples?
Discussing probability, from strongest to weakest:
- will definitely/ will absolutely
- will probably
- may well/might well
- may/might
- could
- could possibly
- coooooould poooooossibly
- won't
- definitely won't/ absolutely won't
- I'd say the odds are about 50/50.
For specific topics, you can add: "(A) will increase/ decrease to chances of (B) happening." for example: "scientists say global warming will increase the chances to harsh weather."
Fallacy of sunk costs: This is when you made a mistake, and keep trying to make that mistake better by spending time/ money on it.
eg: The man from the warm up: "He'd been having a bad night and it was too late to turn back now"
eg: I bought a used car, and it has to be repaired twice a year. Overall it would be cheaper to buy a new car, but I already spent money on the car, so I have to keep using the car!
The time, money or effort you wasted in the past should not lead you to make bad future choices. Each future choice should be considered independently.
Using the information provided, as well as any facts or data that you know of, discuss the odds of the following situations.
- Sales of this product are very low, but we already spent money making and marketing this product, so we have to sell it again next year.
- The price of housing in Tokyo has been rising. So considering the fact that housing prices in cities around the world have been increasing, it's safe to say the odds of Tokyo prices increasing are very good. I think I'll buy an investment property in Tokyo.
- Economists say that a recession happens every seven years. Do you think this will happen in the future? Will it be on schedule?