(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 is well defined and hence it forms a set. (v) The collection of all natural numbers less than 100 is {1, 2, 3, 4, ....., 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.