Math Problem Statement

Given that U = {1, 3, 5, 7, 9, 11, 13, 15, 17}, A = {1, 9, 13, 17}, B = {7, 11, 17}, and C = {3, 5, 15}, determine the following: a) A ∩ B, b) A ∩ C, c) B ∩ U, d) (C ∩ A)', e) A ∪ U, f) A ∩ (B ∩ C'), g) n(A ∩ B'), h) n(A ∪ B ∪ C).

Solution

Let's go through the given sets and determine the required operations.

The universal set UU is: U={1,3,5,7,9,11,13,15,17}U = \{1, 3, 5, 7, 9, 11, 13, 15, 17\}

The given sets are:

  • A={1,9,13,17}A = \{1, 9, 13, 17\}
  • B={7,11,17}B = \{7, 11, 17\}
  • C={3,5,15}C = \{3, 5, 15\}

We will now solve the following:

a) ABA \cap B

The intersection ABA \cap B is the set of elements that are in both AA and BB.

  • A={1,9,13,17}A = \{1, 9, 13, 17\}
  • B={7,11,17}B = \{7, 11, 17\}

Common elements: {17}\{17\}

Thus, AB={17}A \cap B = \{17\}.

b) ACA \cap C

The intersection ACA \cap C is the set of elements common to both AA and CC.

  • A={1,9,13,17}A = \{1, 9, 13, 17\}
  • C={3,5,15}C = \{3, 5, 15\}

No common elements.

Thus, AC=A \cap C = \emptyset (empty set).

c) BUB \cap U

The intersection BUB \cap U is the set of elements common to BB and the universal set UU. Since BB is already a subset of UU, we know:

BU=B={7,11,17}B \cap U = B = \{7, 11, 17\}.

d) (CA)(C \cap A)'

The complement of CAC \cap A, which is (CA)(C \cap A)', means we first find CAC \cap A, and then we take its complement with respect to the universal set UU.

From part b), we found CA=C \cap A = \emptyset.

The complement of \emptyset in UU is the entire universal set UU:

So, (CA)=U={1,3,5,7,9,11,13,15,17}(C \cap A)' = U = \{1, 3, 5, 7, 9, 11, 13, 15, 17\}.

e) AUA \cup U

The union AUA \cup U is the set of elements in either AA or UU (or both). Since AA is already a subset of UU, the result is:

AU=U={1,3,5,7,9,11,13,15,17}A \cup U = U = \{1, 3, 5, 7, 9, 11, 13, 15, 17\}.

f) A(BC)A \cap (B \cap C')

First, we need to find CC' (the complement of CC in UU):

C={3,5,15}C = \{3, 5, 15\}, so C=UC={1,7,9,11,13,17}C' = U - C = \{1, 7, 9, 11, 13, 17\}.

Now, find BCB \cap C':

  • B={7,11,17}B = \{7, 11, 17\}
  • C={1,7,9,11,13,17}C' = \{1, 7, 9, 11, 13, 17\}

Common elements: BC={7,11,17}B \cap C' = \{7, 11, 17\}.

Finally, find A(BC)A \cap (B \cap C'):

  • A={1,9,13,17}A = \{1, 9, 13, 17\}
  • BC={7,11,17}B \cap C' = \{7, 11, 17\}

Common element: {17}\{17\}.

So, A(BC)={17}A \cap (B \cap C') = \{17\}.

g) n(AB)n(A \cap B')

First, find BB' (the complement of BB in UU):

B={7,11,17}B = \{7, 11, 17\}, so B=UB={1,3,5,9,13,15}B' = U - B = \{1, 3, 5, 9, 13, 15\}.

Now, find ABA \cap B':

  • A={1,9,13,17}A = \{1, 9, 13, 17\}
  • B={1,3,5,9,13,15}B' = \{1, 3, 5, 9, 13, 15\}

Common elements: AB={1,9,13}A \cap B' = \{1, 9, 13\}.

The number of elements in ABA \cap B' is 3.

Thus, n(AB)=3n(A \cap B') = 3.

h) n(ABC)n(A \cup B \cup C)

The union ABCA \cup B \cup C is the set of elements in AA, BB, or CC (or all). Let's combine all the sets:

  • A={1,9,13,17}A = \{1, 9, 13, 17\}
  • B={7,11,17}B = \{7, 11, 17\}
  • C={3,5,15}C = \{3, 5, 15\}

Union: ABC={1,3,5,7,9,11,13,15,17}A \cup B \cup C = \{1, 3, 5, 7, 9, 11, 13, 15, 17\}.

The number of elements in this union is 9.

Thus, n(ABC)=9n(A \cup B \cup C) = 9.


Would you like further clarification on any part of this?

Here are five related questions to deepen your understanding:

  1. How do complements and intersections differ in set operations?
  2. What happens when we take the union of a set with the universal set?
  3. Can an empty set have a complement?
  4. Why is ABA \cap B' not the same as ABA \cap B'?
  5. How would the results change if the universal set were different?

Tip: Remember, the complement of a set refers to everything in the universal set except the elements of the given set.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Set Theory
Union
Intersection
Complement
Cardinality

Formulas

A ∩ B = {elements common to both A and B}
A ∪ B = {all elements in A or B or both}
(A ∩ B)' = complement of the intersection with respect to the universal set
n(A) = the number of elements in A

Theorems

Set Union Theorem
Set Intersection Theorem
Set Complement Theorem

Suitable Grade Level

Grades 9-12