Probability - Stage 4

Problem 1 was solved by 70% of the pupils. Problem 2 was solved by 60% of them. Can you work out how many pupils took the exam?

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?

Which of these games would you play to give yourself the best possible chance of winning a prize?

At how many times between 10 and 11 o'clock are all six digits on a digital clock different?

The teacher has forgotten which pupil won which medal. In how many different ways could he give the medals out to the pupils?

Here are two games you can play. Which offers the better chance of winning?

Can you work out which spinners were used to generate the frequency charts?

What is the probability that two pieces of rope are tied together, when Pat ties two loose ends together?

Pizza, Indian or Chinese takeaway? If everyone liked at least one, how many only liked Indian?

Imagine a room full of people who keep flipping coins until they get a tail. Will anyone get six heads in a row?

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

Can you work out the probability of winning the Mathsland National Lottery?

When two closely matched teams play each other, what is the most likely result?

Chances Are

Four cards from a set numbered 1-36 are dealt. What is the probability that they are dealt in order?

There are 10 girls in a mixed class. If two pupils are selected, the probability that they are both girls is 0.15. How many boys are in the class?

In this follow-up to the problem Odds and Evens, we invite you to analyse a probability situation in order to find the general solution for a fair game.

How many marbles need to be taken out to ensure that at least three are of the same colour?

How many different phone numbers are there starting with a 3 and with at most two different digits?

In how many different ways can a row of five "on/off" switches be set so that no two adjacent switches are in the "off" position?

If two girls each take a sweet from each other's bags, what is the probability that they end up with what they started with?

What percentage of people voted for the Broccoli party in the Vegtown election?

Can you work out how many kangaroos Rachel draws in one colour?

6 tiles are placed in a row. What is the probability that no two adjacent tiles have the same letter on them?

Which game offers you the best chance of winning?

If you take two dominoes from a set at random, what is the probability that they 'match'?

How many different ways can I arrange the CDs in my collection?

A coin is flipped 4 times. What is the probability of getting heads at least 3 times?

How many ways can these five faces be ordered?

How can this prisoner escape?

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

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

Will the witch make a profit or loss?