Probability Tree Diagrams Demonstration This resource provides animated

Probability Tree Diagrams – Demonstration This resource provides animated demonstrations of the mathematical method. Check animations and delete slides not needed for your class.

Unconditional Tree Diagrams Ash flips a coin and Peter rolls a dice. These are independent events. What is the probability the result is tails and a 6? Coin Flip Dice Roll ds a e H 6 a D N A 6 H 6 H 1 -5 H 1 -5 Results 6 T 1 -5 T 1 -5

Unconditional Tree Diagram ① Box & Marbles There are black and white marbles in the box. One is picked – and replaced – then another is picked. What is the probability both picks are the same colour? 1 st Pick 2 nd Pick Result Black BB Black White Black BW WB White WW

Unconditional Tree Diagram ② The probability Jill passes her Geography test is 0. 7 The probability Jill passes her Science test is 0. 6 What is the probability she passes only one of the tests? Geography Test Science Test Result Pass PP Fail PF Pass FP Fail FF Pass Fail

Conditional Tree Diagram ③ Woodley United will play two matches against Enfield Wanderers. Why would the probability change? What is P(Win both matches)? 1 st Match 2 nd Match Win WW Win Lose Result Win WL LW Lose LL

Conditional Tree Diagram ④ Box & Marbles There are black and white marbles in the box. One is picked – and not replaced – then another is picked. What is the probability one or more black marbles are picked? What is the probability two marbles of the same colour are picked? 1 st Pick 2 nd Pick Black BB Black White Result Black BW WB White WW

Questions? Comments? Suggestions? …or have you found a mistake!? Any feedback would be appreciated . Please feel free to email: tom@goteachmaths. co. uk