In topology, a coffee cup and a donut are both of genus

Consider a family with a mother, father, and two children. Let A1 = {mother has influenza}, A2 = {father has influenza}, A3 = {first child has influenza}, A4 = {second child has influenza}, B = {at least one child has influenza}, C = {at least one parent has influenza}, and D = {at least one person in the family has influenza}.1 What does A1 ∪ A2 mean? 2 What does A1 ∩ A2 mean? 3 Are A3 and A4 mutually exclusive? 4 What does A3 ∪ B mean? 5 What does A3 ∩ B mean? 6 Express C in terms of A1, A2, A3, and A4. 7 Express D in terms of B and C. 8 What does ?̅1 mean? 9 What does ?̅2 mean?

Refer to a bag containing 20 balls—six red, six green, and eight purple. In how many ways can we select five balls if the balls are considered distinct?

- rhea"aaיLE.aadw

In the game of dominoes each piece is marked with two numbers. The pieces are symmetrical, so that the number pair is not ordered (for example, (2,6)=(6,2)). How many different pieces can be formed using the numbers 1, 2, . . . , n?

In a regular deck of cards  P (face card | diamond) =

A game consists of  spinning a spinner and then rolling a number cube. The spinner is equally likely to land on any 1 of  the 4 colors red, yellow, green, or blue. The number cube is equally likely to land with any of  the 6 sides labeled 1 through 6 up. To win the game, a contestant must either spin red and roll any number or spin a color other than red and roll a 6. In other words, the contestant must either spin red or roll a 6 to win. Draw a rectangular model to go along with this problem.

C d and E

In A ABC 、のこ 3,3,6-2.7, and (=2.3, (alculate (