Activity Questions 1.4

Activity Questions 1.4

Q1. Which of the following sets are same?

(i) {Ankitha, Keerthana, Raju, Suresh}

(ii) {Raju, Ankitha, Keerthana, Raju, Ankitha, Suresh}

(iii) {Keerthana, Suresh, Dheeraj, Raju, Ankitha}

(iv) {Suresh, Raju, Ankitha, Keerthana}

(v) {Dheeraj, Raju, Soumya, Keerthana}

a) (i) and (ii)

b) (iii),(iv) and (v)

c) (i) and (iv)

d) (i),(ii) and (iv)

Solution

Q2. Suppose X = {3, π, Tiger, Ball, -40, Dhoni}. Which of the following statement(s) is(are) true about X?

a) X is not a set because a collection of names of persons and numbers together will not be considered a set

b) X is not a set because “π” cannot be an element of a set.

c) X is a set because X contains items that are from more than two categories

d) X is a set because it is a collection of different well-defined items

Solution

Q3. Which of the following sets is a subset of the set of prime numbers?

○ {2, 3, 5, 8, 11}

○ {3, 5, 7, 11}

○ {2, 5, 7, 27}

○ {5, 9}

Solution

Q4. Which of the following statement(s) is(are) false?

□ Venn diagrams are pictorial representations of sets.

□ Every set is a subset of itself.

□ X ⊆ Y implies that X is a proper subset of Y.

□ Empty set contains only one element i.e. ∅.

Solution

Q5. Which of the following are empty sets?

Set of all perfect squares between 45 and 50

Set of all integers which are both even and odd

Set of all years having 366 days

Set of all prime numbers divisible by 2

Solution

Q6. If X = {a, b, c}, then the power set P(X) =

● {∅, {a}, {b}, {c}, {a, b}, {a, c}, {b, c}, {a, b, c}}

○ {{a}, {b}, {c}, {a, b}, {a, c}, {b, c}, {a, b, c}}

○ {∅, {a}, {b}, {c}, {a, b}, {a, c}, {b, c}}

○ {{a}, {b}, {c}, {a, b}, {a, c}, {b, c}}

Solution

Q7. Let M be the set of all days in a week whose starting letter is either ‘S’ or ‘T’, and N be the set of all months in a year whose ending letter is ‘Y’. What are the cardinalities of M and N respectively?

○ 4, 3

○ 3, 4

○ 4, 4

○ 3, 3

Solution