Question

State which of the following sets are finite and which are infinite. Give reasons for your answer.
(i) A = {x : x ∈ N and x < 100} (ii) B = {x : x ∈ N and x < 5}
(iii) C = {1², 2², 3², …..} (iv) D = {1, 2, 3, 4}
(v) {x : x is a day of the week}.

Answer 1

Hi ,

*******************************************
A set in which the process of counting

of elements comes to an end is called

' finite ' set .

A set which is not finite is called an

' Infinite set ' .

********"********************************

1 ) A = { x : x € N and x < 100 }

A = { 1 , 2 , 3 , ....., 98 , 99 }

A is finite set .

2 ) B = { x : x € N and x < 5 }

B = { 1 , 2 , 3 , 4 }

B is finite set .

3 ) C = { 1² , 2² ,3² , .... }

C is infinite set

4 ) D = { 1 , 2 , 3 , 4 }

D is finite Set .

5 ) E = { x : x is a day of the week }

E = { Sunday , Monday , Tuesday ,

Wednesday, Thursday , Friday , Saturday }

E is finite set .

I hope this helps you.

: )