Probability
Ronan is designing a game.
He has two sets of discs laid face down on a table.
The first set of five discs are labelled 1, 3, 5, 7, 9
The second set of four discs are labelled 2, 4, 6, 8
Players turn over one disc, at random, from each set
and add the numbers together.
Ronan uses the game to raise money for charity.
Each player pays 20p to play the game.
If a player gets a total of exactly 13 they win a bar of
chocolate.
It costs Ronan 50p for each bar of chocolate.
If 100 people play the game, show that Ronan should
expect to raise £12.50 for charity.
Choose level of difficulty
Probability
Help
Step 1:
The first set of five discs are labelled 1, 3, 5, 7, 9
The second set of four discs are labelled 2, 4, 6, 8
Players turn over one disc, at random, from each set
and add the numbers together.
Fill in sample space
diagram.
Two discs are added together
so we must draw a sample
space diagram.
Probability
Each player pays 20p to play the game.
If a player gets a total of exactly 13 they win a bar of
chocolate.
It costs Ronan 50p for each bar of chocolate.
Help
Step 2:
Work out the
probability of
getting exactly 13.
If 100 people play the game, show that Ronan should
expect to raise £12.50 for charity.
How many possible numbers
are there?
How many 13’s are there?
5
7
9
11
5
7
9
11
13
7
9
11
13
15
9
11
13
15
17
Probability
Each player pays 20p to play the game.
If a player gets a total of exactly 13 they win a bar of
chocolate.
It costs Ronan 50p for each bar of chocolate.
If 100 people play the game, show that Ronan should
expect to raise £12.50 for charity.
Help
Step 3:
Work out how much
money he takes.
100 people play the game
each paying 20p.
Probability
Each player pays 20p to play the game.
If a player gets a total of exactly 13 they win a bar of
chocolate.
It costs Ronan 50p for each bar of chocolate.
Help
Step 4:
Work out how many
people you expect to
win.
If 100 people play the game, show that Ronan should
expect to raise £12.50 for charity.
Probability of winning =
3
20
Probability of winning
multiplied by number of
players.
Probability
Each player pays 20p to play the game.
If a player gets a total of exactly 13 they win a bar of
chocolate.
It costs Ronan 50p for each bar of chocolate.
Number of winners = 15
Help
Step 5:
Work out cost of
prizes.
Number of winners multiplied
by cost of prize.
Probability
If 100 people play the game, show that Ronan should
expect to raise £12.50 for charity.
Help
Step 6:
Cost of prizes = £7.50
Work out money
raised.
Cost of prizes subtracted from
money taken.
Money taken = £20
End of Problem
Return to Menu
Probability
Help
Step 1:
The first set of five discs are labelled 1, 3, 5, 7, 9
The second set of four discs are labelled 2, 4, 6, 8
Players turn over one disc, at random, from each set
and add the numbers together.
Fill in sample space
diagram.
Two discs are added together
so we must draw a sample
space diagram.
Probability
Each player pays 20p to play the game.
If a player gets a total of exactly 13 they win a bar of
chocolate.
It costs Ronan 50p for each bar of chocolate.
Help
Step 2:
Work out the
probability of
getting exactly 13.
If 100 people play the game, show that Ronan should
expect to raise £12.50 for charity.
How many possible numbers
are there?
How many 13’s are there?
5
7
9
11
5
7
9
11
13
7
9
11
13
15
9
11
13
15
17
Probability
Each player pays 20p to play the game.
If a player gets a total of exactly 13 they win a bar of
chocolate.
It costs Ronan 50p for each bar of chocolate.
If 100 people play the game, show that Ronan should
expect to raise £12.50 for charity.
Help
Step 3:
Work out how much
money he takes.
100 people play the game
each paying 20p.
Probability
Each player pays 20p to play the game.
If a player gets a total of exactly 13 they win a bar of
chocolate.
It costs Ronan 50p for each bar of chocolate.
Help
Step 4:
Work out how many
people you expect to
win.
If 100 people play the game, show that Ronan should
expect to raise £12.50 for charity.
Probability of winning =
3
20
Probability of winning
multiplied by number of
players.
Probability
Each player pays 20p to play the game.
If a player gets a total of exactly 13 they win a bar of
chocolate.
It costs Ronan 50p for each bar of chocolate.
Number of winners = 15
Help
Step 5:
Work out cost of
prizes.
Number of winners multiplied
by cost of prize.
Probability
If 100 people play the game, show that Ronan should
expect to raise £12.50 for charity.
Help
Step 6:
Cost of prizes = £7.50
Work out money
raised.
Cost of prizes subtracted from
money taken.
Money taken = £20
End of Problem
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Probability
The first set of five discs are labelled 1, 3, 5, 7, 9
The second set of four discs are labelled 2, 4, 6, 8
Players turn over one disc, at random, from each set
and add the numbers together.
Probability
Each player pays 20p to play the game.
If a player gets a total of exactly 13 they win a bar of
chocolate.
It costs Ronan 50p for each bar of chocolate.
If 100 people play the game, show that Ronan should
expect to raise £12.50 for charity.
5
7
9
11
5
7
9
11
13
7
9
11
13
15
9
11
13
15
17
Probability
Each player pays 20p to play the game.
If a player gets a total of exactly 13 they win a bar of
chocolate.
It costs Ronan 50p for each bar of chocolate.
If 100 people play the game, show that Ronan should
expect to raise £12.50 for charity.
Probability
Each player pays 20p to play the game.
If a player gets a total of exactly 13 they win a bar of
chocolate.
It costs Ronan 50p for each bar of chocolate.
If 100 people play the game, show that Ronan should
expect to raise £12.50 for charity.
Probability of winning =
3
20
Probability
Each player pays 20p to play the game.
If a player gets a total of exactly 13 they win a bar of
chocolate.
It costs Ronan 50p for each bar of chocolate.
Number of winners = 15
Probability
If 100 people play the game, show that Ronan should
expect to raise £12.50 for charity.
Cost of prizes = £7.50
Money taken = £20
End of Problem
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Probability
Ronan is designing a game.
He has two sets of discs laid face down on a table.
Hint
Fill in the grid
The first set of five discs are labelled 1, 3, 5, 7, 9
The second set of four discs are labelled 2, 4, 6, 8
Players turn over one disc, at random, from each set
and add the numbers together.
Probability
Ronan is designing a game.
He has two sets of discs laid face down on a table.
Hint
Probability and takings?
The first set of five discs are labelled 1, 3, 5, 7, 9
The second set of four discs are labelled 2, 4, 6, 8
Players turn over one disc, at random, from each set
and add the numbers together.
Ronan uses the game to raise money for charity.
Each player pays 20p to play the game.
If a player gets a total of exactly 13 they win a bar of
chocolate.
It costs Ronan 50p for each bar of chocolate.
If 100 people play the game, show that Ronan should
expect to raise £12.50 for charity.
Probability
Ronan is designing a game.
He has two sets of discs laid face down on a table.
Hint
Costs?
The first set of five discs are labelled 1, 3, 5, 7, 9
The second set of four discs are labelled 2, 4, 6, 8
Players turn over one disc, at random, from each set
and add the numbers together.
Ronan uses the game to raise money for charity.
Each player pays 20p to play the game.
If a player gets a total of exactly 13 they win a bar of
chocolate.
It costs Ronan 50p for each bar of chocolate.
If 100 people play the game, show that Ronan should
expect to raise £12.50 for charity.
End of Problem
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Probability
Ronan is designing a game.
He has two sets of discs laid face down on a table.
Hint
Use the grid below
The first set of five discs are labelled 1, 3, 5, 7, 9
The second set of four discs are labelled 2, 4, 6, 8
Players turn over one disc, at random, from each set
and add the numbers together.
Ronan uses the game to raise money for charity.
Each player pays 20p to play the game.
If a player gets a total of exactly 13 they win a bar of
chocolate.
It costs Ronan 50p for each bar of chocolate.
If 100 people play the game, show that Ronan should
expect to raise £12.50 for charity.
End of Problem
Return to Menu