Introduction
Good afternoon grade 11 class, today's lesson will be based on probability, drawing tree diagrams with and without replacements.
As you already know that probability is how likely is something to happen. Therefore today you will learn how to present probability with/without replacements using tree diagrams.
Below is the description of probability with/without replacements.
- With replacement: The events are independent (chances don't change).
- Without replacement: The events are dependant (The chances change).
Task
As you have the prio-knowledge on how to calculate basic probability using different scenarios. Now you will be required to use the same scenarios to draw tree diagrams presenting probability with replacements and without replacements.
You may use the following link to watch probability videos to prepare you being able to complete your task.
Process
In order to be able to complete your task,
- Firstly you need to know the difference between dependant(outcomes get affected by previous events) and independent events.( outcomes are affected by previous events)
- Secondly you must be able to differentiate scenarios weather they refer to probability with/without replacements. (Already explained the descriptions of replacements)
- Thirdly you must be able to draw tree diagrams, A tree diagram is a tool of mathematical probability that helps to calculate the number of outcomes.
The below are the examples of calculations questions that will be required on the task you have to complete.
Evaluation
With this task you are required to draw a tree diagram and answer questions based to the tree diagram.
1 A bag contains 4 red balls and 4 blue balls. Ronald pick 2 balls at random.
1.1 Construct a tree diagram with replacement on your sheet showing the two selections.
1.2 Calculate the probability that Ronald select the same-coloured ball each time that after each time a ball is selected, it is replaced.
2. Luthando has 7 blue socks and 5 Red socks in his drawer. It is still dark when he gets dressed in the morning and he first grabs a sock and a few. minutes later grabs another sock from his drawer and he does not put the sock into the drawer.
2.1 Draw a tree diagram to show outcomes of the above scenario.
2.2 Calculate the probability that Luthando will wear matching sock.
N.B The answers must be written on an answer sheet and scan it, you may use your cellphone using google drive scanner or cam- scanner
Conclusion
After this lesson the lesson I expect my learners to:
- able to identify a tree diagram with-replacement from without replacements.
- Able to calculate possible outcome using tree diagrams
- And also being able to identify scenarios that need replacements or not.
The learners may use the the following link to enhance their knowledge on probability.
Credits
1.
1.1. 8 Marks
1.2. 5 Marks
2.
2.1 8 Marks
2.2 5 Marks
Teacher Page
Webquest is a very useful and easy tool to adjust on , therefore it is the best tool for teaching and learning .
I had a great experience with it ...
For further information about probability learners may use the following links/videos
Thank you
N.Mabala