Question:

Let $X$, $Y$, $Z$ be subsets of $U$, where $n(U) = 35$, $n(X) = 15$, $n(Y) = 22$, $n(Z) = 14$ and $n(X \cap Y) = 11$, $n(Y \cap Z) = 8$, $n(X \cap Z) = 5$, $n(X \cap Y \cap Z) = 3$ then $n(X \cup Y \cup Z)'$ equals

Updated On: Sep 27, 2023
  • $35$
  • $30$
  • $26$
  • $5$
Hide Solution
collegedunia
Verified By Collegedunia

The Correct Option is D

Solution and Explanation

We know that $n(X \cup Y \cup Z) = n(X) + n(Y) +$ $n(Z) - n (X \cap Y) - n(Y \cap Z) - n(X \cap Z) + n (X \cap Y \cap Z)$ $= (15 + 22 + 14)-(11 + 8 + 5 )+ 3 = 30$ $\therefore n (X \cup Y \cup Z)' = n (U ) - n (X \cup F \cup Z) = 35-30 = 5$
Was this answer helpful?
2
0

Concepts Used:

Sets

Set is the collection of well defined objects. Sets are represented by capital letters, eg. A={}. Sets are composed of elements which could be numbers, letters, shapes, etc.

Example of set: Set of vowels A={a,e,i,o,u}

Representation of Sets

There are three basic notation or representation of sets are as follows:

Statement Form: The statement representation describes a statement to show what are the elements of a set.

  • For example, Set A is the list of the first five odd numbers.

Roster Form: The form in which elements are listed in set. Elements in the set is seperatrd by comma and enclosed within the curly braces.

  • For example represent the set of vowels in roster form.

A={a,e,i,o,u}

Set Builder Form: 

  1. The set builder representation has a certain rule or a statement that specifically describes the common feature of all the elements of a set.
  2. The set builder form uses a vertical bar in its representation, with a text describing the character of the elements of the set.
  3. For example, A = { k | k is an even number, k ≤ 20}. The statement says, all the elements of set A are even numbers that are less than or equal to 20.
  4. Sometimes a ":" is used in the place of the "|".