Sets

Question 1.

State whether or not the following elements form a set; if not, give reason:

(i) All easy problems in your text book.

(ii) All three sided figures.

(iii) The first five counting numbers.

(iv) All the tall boys of your class.

(v) The last three days of the week.

(vi) All triangles that are difficult to draw.

(vii) The first three letters of the English alphabet.

(viii) All tasty fruits.

(ix) All clever boys of class 6.

(x) All good schools in Delhi.

(xi) All the girls in your class, whose heights are less than your height.

(xii) All the boys in your class, whose heights are more than your height.

(xiii) All the problems in your Mathematics book, which are difficult for Amit.

Solution:

Question 1.If set A = {2, 3, 4, 5, 6}, state which of the following statements arc true and which are false :

(i) 2 ∈ A

(ii) 5, 6 ∈ A

(iii) 3, 4, 7 ∈ A

(iv) 2, 8 ∈ A

Solution:

Solution

Question 2.

If set B = {4, 6, 8, 10, 12, 14}. State, which of the following statements is correct and which is wrong :

(i) 5 ∈ B

(ii) 12 ∈ B

(iii) 14 ∈ B

(iv) 9 ∈ B

(v) B is a set of even numbers between 2 and 16.

(vi) 4,6 and 10 are die members of the set B. Also, write the wrong statements correctly.

Solution:

Question 3.

State, whether true or false :

(i) Sets {4, 9, 6,2} and {6, 2, 4, 9} are not the same.

(ii) Sets {0, 1, 3, 9, 4} and {4, 0, 1, 3, 9} are the same.

(iii) Sets {5, 4} and {5, 4, 4, 5} are not the same.

(iv) Sets {8, 3} and {3, 3, 8} are the same.

(v) Collection of vowels used in the word ‘ALLAHABAD’ forms a set.

(vi) If P is the set of letters in the word ‘ROOP’; then P = (p, o, r)

(vii) If M is the set of letters used in the word ‘MUMBAI’, then: M = {m, u, b, a, i}

Solution:

Question 4.

Write the set containing :

(i) the first five counting numbers.

(ii) the three types of angles.

(iii) the three types of triangles.

(iv) the members of your family.

(v) the first six consonants of the English Alphabet.

(vi) the first four vowels of the English Alphabet.

(vii) the names of any three Prime-Ministers of India.

Solution:

Question 5.

(a) Write the members (elements) of each set given below :

(i) {3, 8, 5, 15, 12, 7}

(ii) {c, m, n, o, s}

(b) Write the sets whose elements are :

(i) 2, 4, 8, 16, 64 and 128

(ii) 3, 5, 15, 45, 75 and 90

Solution:

Question 6.

(i) Write the set of letters used in the word ‘BHOPAL’.

(ii) Write the set of vowels used im the word ‘BENGAL’.

(iii) Write the set of consonants used in the word ‘HONG KONG’.

Solution: