Probability

There are 130 NRICH Mathematical resources connected to Probability

problem

Favourite

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?

problem

Favourite

In the playground

Age

5 to 11

Challenge level

What can you say about the child who will be first on the playground tomorrow morning at breaktime in your school?

problem

Favourite

It's a tie

Age

7 to 11

Challenge level

Kaia is sure that her father has worn a particular tie twice a week in at least five of the last ten weeks, but her father disagrees. Who do you think is right?

problem

Favourite

The car that passes

Age

7 to 11

Challenge level

What statements can you make about the car that passes the school gates at 11am on Monday? How will you come up with statements and test your ideas?

game

Game of pig - sixes

Can you beat Piggy in this simple dice game? Can you figure out Piggy's strategy, and is there a better one?

Placeholder: several colourful numbers

problem

Boy or girl?

Age

14 to 16

Challenge level

Will the witch make a profit or loss?

problem

Nine or ten?

Age

11 to 14

Challenge level

Is a score of 9 more likely than a score of 10 when you roll three dice?

Placeholder: several colourful numbers

problem

Dropouts

Age

14 to 16

Challenge level

What percentage of students who graduate have never been to France?

Placeholder: several colourful numbers

problem

Strange dice

Age

11 to 14

Challenge level

If two of these unusually numbered dice are thrown, how many different sums are possible?

problem

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?