Question

Write each set using the descriptive method.
9. {January, February, March}
10. {V, I, E, T, N, A,M}
11. {50, 51, 52, ..., 60}
12. {17, 18, 19, ... , 99}
13. {4, 16, 20, 24, 28}
14. {5, 10, 15, 20, ...)​

Answer 1

9. Set of first three months of a year.
10. Set of alphabets occurring in the word “Vietnam”.
11. Set of natural numbers between 50 and 60 exclusively.
12. Set of natural numbers greater than 16 and less than 100.
13. Set of integers which are multiples of 4 and is less than 32.
14. Set of integers which are multiples of 5.

Note: 11 & 12 can be written interchangeably.

Answer 2

Answer:

9. Set of first three months of a year.

10. Set of alphabets occurring in the word “Vietnam”.

11. Set of natural numbers between 50 and 60 exclusively.

12. Set of natural numbers greater than 16 and less than 100.

13. Set of integers which are multiples of 4 and is less than 32.

14. Set of integers which are multiples of 5.

Step-by-step explanation:

• One way to specify a set is to give a verbal description of its elements. This is known as the Descriptive form of specification.
• The description must allow a concise determination of which elements belong to the set and which elements do not.
• Let us look into some examples to understand how to write the given set in descriptive form.
• Write the following set in descriptive form.
• A  =  {a, e, i, o, u}
• Solution :
• The given set contains vowels. So, we can represent the above set in descriptive form as follows.

• A is the set of all vowels in the English alphabet

9) M= {January, February, March}

Solution:

• The given set contains month's name. So, we can represent the above set in descriptive form as follows.

• M is the set of three months in the calendar

10) W={V, I, E, T, N, A,M}

Solution:

• The given set contains "VIETNAM". So, we can represent the above set in descriptive form as follows.

• W is the set of alphabets occurring in the word “Vietnam”.

11) A={50, 51, 52, ..., 60}

Solution:

• The given set contains 53,54,55,56,57,58,59 So, we can represent the above set in descriptive form as follows.

• A is the set of natural numbers between 50 and 60 exclusively.

12) N= {17, 18, 19, ... , 99}

Solution:

• The given set contains 20,21,22,23,24,25.......99 So, we can represent the above set in descriptive form as follows.

• N is the set of natural numbers greater than 16 and less than 100.

13) F={4, 16, 20, 24, 28}

Solution:

• The given set contains 4,16,20,24,28 So, we can represent the above set in descriptive form as follows.

• F is the set of integers which are multiples of 4 and is less than 32.

14)MF= {5, 10, 15, 20, ...)​

Solution:

• The given set contains 5,10,15,20,....So, we can represent the above set in descriptive form as follows.

• MF is the eet of integers which are multiples of 5.