### There are 16 results

Broad Topics >

Probability > Conditional probability

##### 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?

##### 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?

##### Age 14 to 16 Challenge Level:

The next ten people coming into a store will be asked their
birthday. If the prize is £20, would you bet £1 that two
of these ten people will have the same birthday ?

##### Age 14 to 16 Short Challenge Level:

How can this prisoner escape?

##### 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?

##### Age 14 to 16 Short Challenge Level:

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

##### Age 14 to 16 Challenge Level:

You and I play a game involving successive throws of a fair coin.
Suppose I pick HH and you pick TH. The coin is thrown repeatedly
until we see either two heads in a row (I win) or a tail followed
by. . . .

##### Age 14 to 16 Challenge Level:

Chris and Jo put two red and four blue ribbons in a box. They each pick a ribbon from the box without looking. Jo wins if the two ribbons are the same colour. Is the game fair?

##### 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?

##### Age 14 to 16 Challenge Level:

Can you work out the probability of winning the Mathsland National Lottery? Try our simulator to test out your ideas.

##### 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. . . .

##### Age 11 to 14 Challenge Level:

Alison and Charlie are playing a game. Charlie wants to go first so Alison lets him. Was that such a good idea?

##### Age 14 to 18 Challenge Level:

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

##### Age 14 to 16 Challenge Level:

In how many different ways can I colour the five edges of a
pentagon red, blue and green so that no two adjacent edges are the
same colour?

##### Age 11 to 14 Challenge Level:

Your partner chooses two beads and places them side by side behind a screen. What is the minimum number of guesses you would need to be sure of guessing the two beads and their positions?

##### Age 11 to 14 Challenge Level:

7 balls are shaken in a container. You win if the two blue balls
touch. What is the probability of winning?