Question

Which of the following sets are finite or infinite :

(i) The set of months of a year.

(ii) { 1, 2, 3, ........}

(iii) { 1, 2, 3, ........ 99,100}

(iv) The set of positive integers greater than 100.

(v) The set of prime numbers less than 99.

Answer 1

(i) Since number of months in a year is 12, i.e., finite, so set of months of a year is finite.

(ii) Set { 1, 2, 3, .......................} is infinite because have infinite number of elements.

(iii) {1, 2, 3, ................ 99, 100} is finite set, since here number of elements are finite.

(iv) Given set is infinite, since here number of elements are infinite.

(v) Given set is finite, since prime number less than 99 are countable.