Question math help

Question

The probability of winning a certain game is .2

(a) Draw and label a tree diagram if you play this game twice

(b) Find P( Win exactly one time)

(c) Find P( Win at least one time)

Answer 1

Melanie

(a) You will have 2 sets of branches, one for first game, one for second.

For first game, one branch (win), probability 0.2, other branch lose probability 1-0.2 = 0.8

Then at the end of these 2 branches you draw 2 more branches for the 2nd game and calculate the end probabilities at the end of the four branches. (WW, WL, LW, LL).

p(WW) = 0.2 X 0.2 = 0.04, p (WL) = 0.2 x 0.8 = 0.16 etc

(b) Use your tree diagram for this. Add up probabilities at end of branches where you win exactly one time

(should get 0.08).

(c) Use tree diagram. Should get 0.36. Another way to look at this = p (win at least one time) = 1 - p (lose both).

Mike