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) The set of months of a year is a finite set because it has 12 elements.

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(ii) {1, 2, 3 …} is an infinite set as it has infinite number of natural numbers.

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(iii) {1, 2, 3 …99, 100} is a finite set because the numbers from 1 to 100 are finite in number.

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(iv) The set of positive integers greater than 100 is an infinite set because positive integers greater than 100 are
infinite in number.

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(v) The set of prime numbers less than 99 is a finite set because prime numbers less than 99 are finite in number.