Resources tagged with: Combining probabilities

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There are 24 NRICH Mathematical resources connected to Combining probabilities, you may find related items under Probability.

Broad Topics > Probability > Combining probabilities

The Better Bet

Age 14 to 16 Challenge Level:

Here are two games you have to pay to play. Which is the better bet?

Put Out

Age 16 to 18 Challenge Level:

After transferring balls back and forth between two bags the probability of selecting a green ball from bag 2 is 3/5. How many green balls were in bag 2 at the outset?

Snooker Frames

Age 16 to 18 Challenge Level:

It is believed that weaker snooker players have a better chance of winning matches over eleven frames (i.e. first to win 6 frames) than they do over fifteen frames. Is this true?

Knock-out

Age 16 to 18 Challenge Level:

Before a knockout tournament with 2^n players I pick two players. What is the probability that they have to play against each other at some point in the tournament?

Do You Brush Your Teeth Every Day?

Age 14 to 18 Challenge Level:

How can we find out answers to questions like this if people often lie?

Odd Dice

Age 14 to 16 Short Challenge Level:

These strange dice are rolled. What is the probability that the sum obtained is an odd number?

Statins and Risk

Age 14 to 16 Challenge Level:

"Statins cut the risks of heart attacks and strokes by 40%"
Should the Professor take statins? Can you help him decide?

How Risky Is My Diet?

Age 11 to 16 Challenge Level:

Newspapers said that eating a bacon sandwich every day raises the risk of bowel cancer by 20%. Should you be concerned?

Chance Combinations

Age 11 to 14 Challenge Level:

Can you design a bingo board that gives you the best chance of winning?

Dicey Decisions

Age 16 to 18 Challenge Level:

Can you devise a fair scoring system when dice land edge-up or corner-up?

Lottery Simulator

Age 7 to 16 Challenge Level:

Use this animation to experiment with lotteries. Choose how many balls to match, how many are in the carousel, and how many draws to make at once.

At Least One...

Age 11 to 14 Challenge Level:

Imagine flipping a coin a number of times. Can you work out the probability you will get a head on at least one of the flips?

Same Number!

Age 14 to 16 Challenge Level:

If everyone in your class picked a number from 1 to 225, do you think any two people would pick the same number?

Molecular Sequencer

Age 14 to 18 Challenge Level:

Investigate the molecular masses in this sequence of molecules and deduce which molecule has been analysed in the mass spectrometer.

Heavy Hydrocarbons

Age 14 to 18 Challenge Level:

Explore the distribution of molecular masses for various hydrocarbons

Taking Chances

Age 11 to 14 Challenge Level:

This article, for students and teachers, is mainly about probability, the mathematical way of looking at random chance and is a shorter version of Taking Chances Extended.

Taking Chances Extended

Age 14 to 18

This article, for students and teachers, is mainly about probability, the mathematical way of looking at random chance.

Voting Paradox

Age 14 to 18 Challenge Level:

Some relationships are transitive, such as `if A>B and B>C then it follows that A>C', but some are not. In a voting system, if A beats B and B beats C should we expect A to beat C?

Fixing the Odds

Age 14 to 16 Challenge Level:

You have two bags, four red balls and four white balls. You must put all the balls in the bags although you are allowed to have one bag empty. How should you distribute the balls between the two. . . .

Win or Lose?

Age 14 to 16 Challenge Level:

A gambler bets half the money in his pocket on the toss of a coin, winning an equal amount for a head and losing his money if the result is a tail. After 2n plays he has won exactly n times. Has. . . .

Marbles and Bags

Age 14 to 16 Challenge Level:

Two bags contain different numbers of red and blue marbles. A marble is removed from one of the bags. The marble is blue. What is the probability that it was removed from bag A?

Gambling at Monte Carlo

Age 14 to 16 Challenge Level:

A man went to Monte Carlo to try and make his fortune. Is his strategy a winning one?

Snooker

Age 16 to 18 Challenge Level:

A player has probability 0.4 of winning a single game. What is his probability of winning a 'best of 15 games' tournament?

Squash

Age 16 to 18 Challenge Level:

If the score is 8-8 do I have more chance of winning if the winner is the first to reach 9 points or the first to reach 10 points?