Najwa and Zuki play a game.

They put two red and two blue ribbons in a box. They pull out two ribbons at the same time without looking at the colours.

Najwa wins if both ribbons are the same colour.

Zuki wins if the two ribbons are different colours.

Is this a fair game?

List all the different possible events that can happen each time you play this game, for example (red and red) …

Now suppose that you change the game so that there are two red and four blue ribbons in the box? Is this a fair game? Why or why not?

Also see www.nrich.maths.org/919

### 37 Responses to Grades 5 to 12 In a Box

1. Zoe says:

This was not a fair game,I would put the same number of ribbons i.e four red and four blue ribbons so that the have equal chances of winning the game.

• Steve says:

i think this is not a fair game because the red and blue ribbons must be equal in number

2. Dane says:

It is not a fair game seeing as the probability that it will be the same color is 14/30 and different colors 16/30. If we wanted to make it a fair game we had to have the same amount of red ones as blue ones. Am I correct in my reasoning?

3. Mlu says:

This is a fair game, since both players are given an equal opportunity to play the game. The rules are fair to both of them and they have an equal opportunity of winning the game. This question is suitable for Grade 8 and 9 learners.

4. Yeye says:

This game is not a fair game.To be fair both players must equal chances,two red ribbons and blue ribbons.This will be suitable for grade8.

5. Thandi says:

The game was not fair.colours should be equal

6. Babes says:

This is not a fair game because they were using different number of ribbons,to be fair there should be an equal number of ribbons.

7. Mlu says:

I would use this exercise to Introduce probability in my grade 8 or 9 class. To modify the exercise I would use different colored marbles.

8. Sharin says:

It is a not a fair game.I will make it an independent game so that every draw could be 50%(even).

9. Fufu Ornjenjie says:

This is not a fair game because the ribbons are not equal in number in a box.

10. Sharin says:

colours should also be equal.

11. Yeye says:

I would use the activity to introduce my lesson ,and learners will be in groups discussing about all the possible outcomes.Each group will report back ,also giving reasons .I would use this activity in grade 8.

12. Lizeka says:

This is not a fair game because there are more chances of choosing different colours of ribbons. To make this game fair there must be equal number of red and blue ribbons.

• Slagget says:

I do not take it as a fair game.The two players must have equal chances of picking both ribbons.

13. Steve says:

i would use it in grade 7 to introduce the probability

14. Pumeza says:

This is Not a fair game because Najwa is having more chances to win a game than Zuki.In order to be a fair game we need to put the same number of ribbons that means four blue ribbon and four red ribbons.

15. Mvellie says:

This is an unfair game because the chances are not equal.There must be fifty chances of winning a game.

16. Lwandle says:

This is not a fair game. They must have equal number of ribbons,that is having four ribbons in each colour.Let them play the game using equal number of ribbons.They will observe different outcomes.

17. Bheki says:

This kind of question will be suitable to introduce probability at grade 6 as it would allow learners to talk using a mathematical language and developing rules of their own. I think it would be more nicer if i use different sweets instead of a ribbon as the learners will be talking about words like unfair and fair.

18. Venny says:

This is not a fair game because there are more blue ribbons than red ribbons. If we want to make it fair we should take out the two blue ribbons.

19. Soso says:

It is not a fair game since the number of ribbons is not the same .Najwa have more chances of winning the game

I will not use example for introductory purposes because learners will get confused of when u talk equal chances probability

20. Christobel says:

This is not a fair game, for a game to be fair there should be equal chances of winning. This kind of a question is suitable for Grade 7 and Grade 8 learners. To correct it, I would put equal number of ribbons. I my class would make use of the similar type of a question but make use the objects they all know e.g. marbles.

21. Pro Khumalo says:

The game was not fair,colors should be equal for the game to be fair.

22. Judith says:

This is not a fair game because the players do not have equal chance of winning.

The game was not fair because the number of red ribbons must be equal to the number of blue marble so that the two have equal chances of winning the game.

24. Sylvia says:

The game was not fair.The red and the blue ribbon must be equal.

25. Tuleka says:

no the game is not fair, i would put the same number of ribbons. three red ribbons and three blue ribbons.

No ,the game was not fair because the number of red ribbons were more than blue ribbons.

27. Jenita says:

A fair game is when both people have an equal opportunity of winning it. Therefore this game is not fair because these two people do not have equal chances of winning. For it to be fair, there should be an equal number of ribbons e.g 2 red and 2 blue.

28. Sbu says:

the game was not fair because the number of ribbons taken were not the same.

29. Godwin says:

It is not a fair game because from my understanding it is a dependent event meaning when one ribbon is taken out it is not being replaced.Zuki has a 16/30 chances of winning the game whereas Najwa has a chance of 14/30 chance of winning the game.It is giving Zuki an unfair advantage.

not a fair game since zuki has more chances of winning a game than najwa

31. Godwin says:

For it to be a fair game the rules have to be changed to equal numbers of ribbons and the rule is zuki wins if its red and najwa wins if blue

32. Mmboneni says:

Is not a fair game because Zuki has more chance than Najwa

33. Kgaogelo says:

It is not fair , since Najwa is 7/15 and Zuki is 8/15 the game must be fair if there is equal chances of winning

34. D.Man says:

when we look the game there are 53% and 47% chance on players that mean there are an even chances