Page 11 - 091math-wb-w3-(sets)

WORKBOOK

EXERCISES-1

A) Multiple Choice Questions 7) A = {a, b, {c}, {d, e}, d, e, {∅}} is given. Which of
the following is/are true?
1) Lara listed the set of all letters in the word
“library” as shown below. What is wrong with this ( ) d ∈ A
set?
( ) {d} ∈ A

G = {l, i, b, r, a, r, y}
( ) {d, e} ∈ A
( ) G capital letter is used to represent this set. ( ) {b} ∈ A
( ) It uses curly braces.
( ) It uses commas. ( ) ∅ ∈ A
( ) The elements in this set are not unique. ( ) {b, {c}} ∈ A
( ) y ∈ G
( ) c ∈ A
2) G = {…, -2, -1, 0}. What type of set is G?
8) Express the following sets in list notation.
( ) Empty a) A= {x: x is a digit less than 7}
( ) Finite
( ) Infinite
( ) Zero
( ) None of the above
b) B= {x: x is an integer smaller than 27 and
a multiple of 3}
3) If A   ,x( y . x : ) y  , 6 y , x  Z , what is n(A)?

( ) 8 ( ) 7 ( ) 6 ( ) 5 ( ) 4

4) Which one is not an empty set? c) C= {x: x(x+2)(x – 1) = 0, x∈Z}


( )  
( )  x:x  , 2 x is a prime number 
( )  :x  3 x  , 0 x is a natural number  9) Write the following sets in set-builder
( )  x:x 2  1 x , 0  R  (predicate) notation.
a) M={0, 2, 4, 6, 8, 10, 12}
( )  6:x  x  , 7 x Z 

B) Open Ended Questions
b) N={Sunday, Saturday}
5) In your own words, describe a set.

c) K={2, 3, 5, 7, 1

6) In your own words, describe the empty set,
finite set and infinite set.

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