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 eleven 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 Munahi 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.
(i) The collection of all months of a year beginning with J is (January, June, July), which is well defined and hence it forms a set.
(ii) The collection of most talented writers of India is not well defined because opinions about 'most talented writers' vary from person to person and hence it does not form a set.
(iii) A team of eleven best-cricket batsmen of the world is not well defined because opinions about 'best-cricket batsmen' vary from person to person and hence it does not form a set.
(iv) The collection of all boys in your class in well defined and hence it forms a set.
(v) The collection of all natural numbers less than 100 is {1, 2, 3, .... 99}, which is well defined and hence it forms a set.
(vi) A collection of novels written by the writer Munshi Prem Chand is well defined and hence it forms a set.
(vii) The collection of all even integers is {....., -4, -2, 0, 2, 4} which is well defined and hence it forms a set.
(viii) The collection of questions in this chapter is well defined and hence it forms a set.
(ix) A collection of most dangerous animals of the world is not well defined because opinions about 'most dangerous animals' vary from person to person and hence it does not form a set.