week 2

Question 1

the sum of all branches coming out of the right side of a node equals

Answer 1

the value on the left branch leading into the node

Question 2

the size of a set is equal to to

Answer 2

the sum of all branches leading into (coming from the left of) nodes with that set as the node’s name

Question 3

the size of the universal set is

Answer 3

the sum of branches coming out of the root node

Question 4

the size of a set is

Answer 4

equal to the sum of the rightmost values of all the paths that are subsets of that set

Question 5

for any set the number of subsets is

Answer 5

2 ^n(a)

number of elements in A

Question 6

multiplication rule (fundamental counting principle)

Answer 6

when you have subsequent choices ( and then ) you can compute the total number of possibilities by multiplying the number of choices together

Question 7

addition rule

Answer 7

when you have contradictory choices ( one of, or, but not both ) you can compute the total number of possibilities by adding the number of choices together

Question 8

number of ways an event can happen
selection with replacement

Answer 8

when choosing from a collection of n objects k times, and each time the same n objects are available, the total number of choices is n^k

Question 9

counting the opposite

Answer 9

• count the total number of objects possible
• count the number of objects that don’t satisfy the condition
• subtract don’t satisfy from total possible