Set Theory

 Definition of a Set.

A collection of definite and distinct things is called set.

For example: V = ( a, e, i, o, u)

A set can be represented in three ways-

1.    By Words

2.    Tabular Method/Roster Method

3.    Set Builder Method/ Rule Method

Question: Represent the set V = ( a, e, i, o, u) in words.

Ans. The set of vowels of English Alphabet.

Question: Represent the set A = ( 2, 4, 6, 8, 10, 12, 14...............)

Ans. The set of Even Natural Number.

Question: Represent the following set in Tabular Method or Roster Method.

i.    The set of Prime Number less than 20.

ii.    The set of months in a year starting with the letter J

Solution: i. A = (2, 3, 5, 7, 11, 13, 17, 19)

               ii. B = (January, June, July)

Question: Represent the following set by Set Builder Method or Rule Method.

                i.    A = (2, 3, 5, 7, 11, 13, 17, 19)

               ii.    B = (January, June, July)

Solution: i. A = ( x/x, is a prime number x<20)

                ii. B = ( x/x is a month in English Calendar starting with the letter J) 


Comments

Post a Comment

Popular posts from this blog

Logical Sequence

                                                     Topic: Logical Sequence, ...............................................................................................................................   Question: Arrange the words given below in a meaningful sequence. 1. Key 2. Door 3. Lock 4. Room 5. Switch on   i.               5, 1, 2, 4, 3 ii.             4, 2, 1, 5, 3 iii.            1, 3, 2, 4, 5 iv.            1, 2, 3, 5, 4   Answer:  Option is (iii) Explanation: The correct order is : Key ...
Read more

Missing Number, Odd Man Out, Coding & Decoding

  Topic:   Missing Numbers, Odd man Out, Coding & Decoding …………………………………………………………………………………………………   Question:Determine the missing number in the given sequence   1, 3, 5, 7, 11, __, 17, 19 Solution: Given sequence: 1, 3, 5, 7, 11, ?, 17, 19 The given sequence is in ascending order and it is a prime number list. As we know, prime numbers are the numbers that are divisible by 1 and the number itself only. As a result, the missing number in the sequence should be 12. Hence, the sequence becomes 1, 3, 5, 7, 11,  13 , 17, 19. 2. Find the missing number from the following? 6 9 15 8 12 20 4 6 ? Solution: Using the row-wise logic, we can find the missing number from the given table. The logic used here is first element in the row + second element in the row = third element in the row: In first row, 6 + 9 = 15 In second row, 8 + 12 = 20 Sim...
Read more