



 
Hi Sandy, To draw a tree diagram you think of the process happening in steps. In this case I made the first step selection of a meat and the second step selection of a toy. If these two actions are random then the probabilities of selecting chicken, hamburger or fish are each 1/3. There are twice as many balls as Frisbees and an equal number of parachutes and Frisbees so the probability of selecting a ball is 1/2 and the probability of selecting a Frisbee is 1/4 and the probability of selecting a parachute is 1/4. Here is my tree. You can now read some probabilities off the diagram by tracing a path from the root of the tree to its top. For example the probability of a child receiving a hamburger and a Frisbee is 1/3 × 1/4 = 1/12 and the probability of a child receiving fish and a ball is 1/3 × 1/2 = 1/6. Thus the probability that a child receives either a hamburger and a Frisbee or fish and a ball is 1/12 + 1/6 = 1/4. I hope this helps,  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 