Q.1: Which of the following are sets. Explain your answer. (a). The collection of all day in a week which have the first letter S. (b). The collection of ten most famous singers of India. (c). A group of best football strikers of the world. (d). The collection of all girls in your school. (e). The collection of all odd numbers below 50. (f). A collection of poems written by the poet Shakespeare. (g). The collection of all prime numbers. (h). The collection of questions in science book. (i). A collection of most dangerous reptiles in India.
Answers
Solution:
(i) The collection of all months of a year beginning with the letter J is a well-defined collection of objects because one can definitely identity a month that belongs to this collection. Hence, this collection is a set.
(ii) The collection of ten most talented writer of India is not a well-defined collection because the criteria for determining a writer’s talent vary from person to person. Hence, this collection is not a set.
(iii) A team of eleven best cricket batsmen of the world is not a well-defined collection because the criteria for determining a batsman’s talent may vary from person to person. Hence, this collection is not a set.
(iv) The collection of all boys in your class is a well-defined collection because you can definitely identify a boy who belongs to this collection. Hence, this collection is a set.
(v) The collection of all natural numbers less than 100 is a well-defined collection because one can definitely identify a number that belongs to this collection. Hence, this collection is a set.
(vi) A collection of novels written by the writer Munshi Prem Chand is a well-defined collection because one can definitely identify a book that belongs to this collection. Hence, this collection is a set.
(vii) The collection of all even integers is a well-defined collection because one can definitely identify an even integer that belongs to this collection.
Hence, this collection is a set.
(viii) The collection of questions in this chapter is a well-defined collection because one can definitely identify a question that belongs to this chapter. Hence, this collection is a set.
(ix) The collection of most dangerous animals of the world is not a well-defined collection because the criteria for determining the dangerousness of an animal can vary from person to person. Hence, this collection is not a set.
Answer:
- He declared Sunday as the first day of the week and introduced seven days in a week
- Top 10 singers of Bollywood of all time
- AR Rahman- Top 10 Bollywood singers.
- Arijit Singh- Top 10 Bollywood singers.
- Shreya Ghoshal- Top 10 Bollywood singers.
- Sonu Nigam- Top 10 Bollywood singers.
- Shaan- Top 10 Bollywood singers.
- Udit Narayan- Top 10 Bollywood singers.
- KK- Top 10 Bollywood singers.
- Alka Yagnik- Top 10 Bollywood singers.
- Messi is still the best player on the planet at 32 years old and he may well hold this title next year. Other notable mentions for this slot come in the shape of Karim Benzema and Luis Suarez – two strikers who have dominated the game for years on end