# List all the elements of the following sets :

(i) A = {x : x is an odd natural number}

(ii) B = {x : x is an integer, -1/2 < x < 9/2 }

(iii) C = {x : x is an integer, x^{2} ≤ 4}

(iv) D = {x : x is a letter in the word “LOYAL”}

(v) E = {x : x is a month of a year not having 31 days}

(vi) F = {x : x is a consonant in the English alphabet which precedes k }

**Solutions:**

(i) A = { x : x is an odd natural number}

From this, A should include all the natural numbers that are odd.

A = {1, 3, 5, 7, 9....}

(ii) B = { x : x is an integer; - 1/2 < x < 9/2}

We see that

- 1/2 = - 0.5 and 9/2 = 4.5

Therefore,

B = {0, 1, 2, 3, 4}

(iii) C = { x : x is an integer; We see that x^{2} ≤ 4 }

(0)^{2} = 0, i.e., (0)^{2} < 4

(- 1)^{2} = 1, i.e., (- 1)^{2} < 4

(- 2)^{2} = 4, i.e., (- 2)^{2} = 4

(- 3)^{2} = 9, i.e., (- 3)^{2} > 4

Therefore,

C = {- 2, - 1, 0, 1, 2}

(iv) D = ( x : x is a letter in the word “LOYAL”)

D = {L, O, Y, A}

(v) E = { x : x is a month of a year not having 31 days}

E = {February, April, June, September, November}

(vi) F = { x : x is a consonant in the English alphabet which precedes k}

F = {b, c, d , f, g, h, j}

NCERT Solutions Class 11 Maths Chapter 1 Exercise 1.1 Question 5

## List all the elements of the following sets : (i) A = {x : x is an odd natural number} (ii) B = {x : x is an integer, 1/2 – < x < 9/2 } (iii) C = {x : x is an integer, x² ≤ 4} (iv) D = {x : x is a letter in the word “LOYAL”} (v) E = {x : x is a month of a year not having 31 days} (vi) F = {x : x is a consonant in the English alphabet which precedes k }.

**Summary:**

We are asked to list all the elements of the following sets. We found that

(i) A = {x : x is an odd natural number} = {1, 3, 5, 7, 9....}

(ii) B = {x : x is an integer, 1/2 – < x < 9/2 } = {0, 1, 2, 3, 4}

(iii) C = {x : x is an integer, x^{2} ≤ 4} = {- 2, - 1, 0, 1, 2}

(iv) D = {x : x is a letter in the word “LOYAL”} = {L, O, Y, A}

(v) E = {x : x is a month of a year not having 31 days} = {February, April, June, September, November}

(vi) F = {x : x is a consonant in the English alphabet which precedes k } = {b, c, d , f, g, h, j}

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