Notes 2/18 
Sean, Kevin

x - 0 sequence length 5

[Here is a tree diagram where all possibilites are drawn out.]


There are 13 possibilities



How many ways are there to get from point A to point B on a 6x4 grid, stoping by point X?

You first split it up into two part. 
You solve both parts then multiply them together.



Eric has 12 children and wants to chose 4 to go to the basketball game with him. How many combinations of children are there?

(12)		12!/4!3!  
( 4)      or 



Toss 5 coins, whats the probability that you will get <=3 heads?   

#favorable/#total
?/2(2)(2)(2)(2)

Step 1: # of ways to get <= 3 heads
	4 cases


Step 2: 0 heads: 1  : TTTTT
	1 heads: 5  : HTTTT
	2 heads: 10 : HHTTT
	3 heads: 10 : HHHTT

Step 3: add 1,5,10,10  and get 26

Step 4: 26/2(2)(2)(2)(2) or 26/32 = 13/16




Toss 2 dice, chances that sum is greater than 7

total# = 6*6 = 36

P[Sub >7] = favorable/total


 123456
1
2     x  = 15/36 = 5/12
3    xx
4   xxx
5  xxxx
6 xxxxx