State whether each of the following set is finite or infinite

State whether each of the following set is finite or infinite :

(i) The set of lines which are parallel to the x-axis
(ii) The set of letters in the English alphabet
(iii) The set of numbers which are multiple of 5
(iv) The set of animals living on the earth
(v) The set of circles passing through the origin (0, 0)
Answer

(i) Infinity numbers of parallel line to the x-axis are possible.
Hence, the set of lines which are parallel to the x-axis is an infinite set

(ii) There are 26 elements in English alphabet.
Hence, the set of letters in the English alphabet is a finite set

(iii) Multiples of 5 are infinite. Hence the set of numbers which are multiple of 5 is an infinite set.

(iv) The number of animals living on the earth is a certain number.
Hence the set of animals living on the earth is a finite set.

(v) infinity number of circle can be draw using different radius using origin (0 ,0) as a centre.
Hence the set of circles passing through the origin (0, 0) is an infinite set