Probability - Stage 4

list

Probability short problems - age 14-16

Age

14 to 16

A collection of short problems on probability.

problem

One or both

Age

14 to 16

Challenge level

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?

problem

Different digital clock

Age

14 to 16

Challenge level

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

problem

Medal ceremony

Age

14 to 16

Challenge level

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

problem

Tying the rope

Age

14 to 16

Challenge level

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

problem

Takeaway time

Age

14 to 16

Challenge level

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

problem

Descending deal

Age

14 to 16

Challenge level

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

problem

Two girls

Age

14 to 16

Challenge level

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?

problem

Collecting marbles

Age

14 to 16

Challenge level

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

problem

Phone call

Age

14 to 16

Challenge level

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

problem

Switch on

Age

14 to 16

Challenge level

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?

problem

Swapping sweets

Age

14 to 16

Challenge level

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?

problem

Counting kangaroos

Age

14 to 16

Challenge level

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

problem

Domino match

Age

14 to 16

Challenge level

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

problem

Flipping coins

Age

14 to 16

Challenge level

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

problem

CD collection

Age

14 to 16

Challenge level

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

problem

XOXOXO

Age

14 to 16

Challenge level

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

problem

The better choice

Age

14 to 16

Challenge level

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

problem

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?

problem

Last one standing

Age

14 to 16

Challenge level

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

problem

Mathsland national lottery

Age

14 to 16

Challenge level

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

problem

Chances are

Age

14 to 16

Challenge level

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

problem

In a box

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?

problem

Odds and evens made fair

Age

14 to 16

Challenge level

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.