Solve the Puzzle questions

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Let’s learn a way to investigate these types of questions that people in the business world use.

Slide 13

Notation

First some set notation symbols.

Assume that A is the set of even natural numbers between 1 and 10 inclusive.

There are 5 elements in set A:

A = {2,4,6,8,10}

Another way to say this is #(A) = 5

Slide 14

Think of it as saying… # (A) = 5 the number of elements in set A equals 5

Slide 15

Let U be the set of all students in the class.

Let M be the set of students who watch MTV.

Let G be the set of students who play video games.

We know that #(U) = 30.

We know that #(M) = 17.

We know that #(G) = 12.

Slide 16

Let U be the set of all students in the class.

Let M be the set of students who watch MTV.

Let G be the set of students who play video games.

We know that #(U) = 30.

We know that #(M) = 17.

We know that #(G) = 12.

M

G

Slide 17

U

M

G

We know that #(U) = 30, #(M) = 17, and #(G) = 12.

Think of ALL the students in the class being represented by points inside the rectangle U.

Slide 18

U

M

G

We know that #(U) = 30, #(M) = 17, and #(G) = 12.

Inside circle M are the 17 students who watch MTV.

Slide 19

U

M

G

We know that #(U) = 30, #(M) = 17, and #(G) = 12.

Inside the circle M are the 17 students who watch MTV.

Inside circle G are the 12 students who play video games.

Slide 20

U

M

G

We know that #(U) = 30, #(M) = 17, and #(G) = 12.

Inside the circle M are the 17 students who watch MTV. Inside the circle G are the 12 students who play video games.

The 5 students who watch MTV and play video games

are in the region inside both circles which is colored green.

Slide 21

U

M

G

We know that #(U) = 30, #(M) = 17, and #(G) = 12.

The green region (5 students) is denoted by

M G, which is read, “M intersect G”

or “the intersection of M and G.”

Slide 22

U

M

G

We know that #(U) = 30, #(M) = 17, and #(G) = 12.

Moreover, #(M G) = 5