Which of the following are sets? Justify your answer.(i)  The collection of all the months of a year beginning with the letter J.(ii) The collection of ten most talented writers of India.(iii) A team of elevens best–cricket batsmen of the world.(iv) The collection of all boys in your class.(v) The collection of all natural numbers less than 100.(vi) A collection of novels written by the writer Munshi Prem Chand.(vii) The collection of all even integers.(viii) The collection of questions in this chapter.(ix)  A collection of most dangerous animals of the world.

Solution: (i) The collection of all the months of a year beginning with the letter J.
-$\left\{Jauary,Jue,J\underline{y}\right\}$ -It is a set as it will always have these 3 values.

(ii) The collection of ten most talented writers of India. -
It is not a set as ten most talented writers is personal choice and it will vary from person to person.

(iii) A team of eleven best–cricket batsmen of the world.-
It is not a set as eleven best–cricket batsmen is personal choice and it will vary from person to person.

(iv) The collection of all boys in your class.-
It is a set as it will always have same elements.

(v) The collection of all natural numbers less than 100.
- $\left\{1,2,3\dots 99\right\}$ It is a set as it will always have these elements.

(vi) A collection of novels written by the writer Munshi Prem Chand.
- It is a set as it will always have same elements.

(vii) The collection of all even integers.
- It is a set as it will always have same elements.

(viii) The collection of questions in this Chapter.
- It is a set as it will always have same elements.

(ix) A collection of most dangerous animals of the world.-It is not a set as most dangerous animals of the world is personal choice and it will vary from person to person.