5. Write the cardinal number for each of the following.
(a) X = The set of months in a year
(b) Y = The set of letters in the word INTELLIGENT
(c) Z = The set of prime numbers from 2 to 11
(d) P = {x : x is an even prime number}
(e) Q = {x : x is a quadrilateral having 5 sides}
(f) R = {x : x ∈ I, -5 < x < 2}
(g) S = {x | x ∈ W, x + 2 < 9}
Answers
(a) X = The set of months in a year
X = { January, February, March, April, May, June ,..., December }
Cordinal number of X
= n(X)
= Number of elements in set X
= 12
(b) Y = The set of letters in the word INTELLIGENT
Y = { I, N, T, E, L, G, T}
Cordinal number of Y
= n(Y)
) = Number of elements in set Y
= 7
(c) Z = The set of prime numbers from 2 to 11
Z = { 3, 5, 7 }
Cordinal number of Z
= n(Z)
) = Number of elements in set Z
= 3
(d) P = {x : x is an even prime number}
P = { 2 }
Cordinal number of P
= n(P)
) = Number of elements in set P
= 1
(e) Q = {x : x is a quadrilateral having 5 sides}
Q = { }
Cordinal number of Q
= n(Q)
) = Number of elements in set Q
= 0
(f) R = {x : x ∈ I, -5 < x < 2}
R = { -4,-3,-2,-1,0,1 }
Cordinal number of R
= n(R)
) = Number of elements in set R
= 6
(g) S = {x | x ∈ W, x + 2 < 9}
S = { 0,1,2,3,4,5,6}
Cordinal number of S
= n(S)
) = Number of elements in set S
= 7
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Answer:
(a) X = The set of months in a year
X = { January, February, March, April, May, June ,..., December }
Cordinal number of X
= n(X)
= Number of elements in set X
= 12
(b) Y = The set of letters in the word INTELLIGENT
Y = { I, N, T, E, L, G, T}
Cordinal number of Y
= n(Y)
) = Number of elements in set Y
= 7
(c) Z = The set of prime numbers from 2 to 11
Z = { 3, 5, 7 }
Cordinal number of Z
= n(Z)
) = Number of elements in set Z
= 3
(d) P = {x : x is an even prime number}
P = { 2 }
Cordinal number of P
= n(P)
) = Number of elements in set P
= 1
(e) Q = {x : x is a quadrilateral having 5 sides}
Q = { }
Cordinal number of Q
= n(Q)
) = Number of elements in set Q
= 0
(f) R = {x : x ∈ I, -5 < x < 2}
R = { -4,-3,-2,-1,0,1 }
Cordinal number of R
= n(R)
) = Number of elements in set R
= 6
(g) S = {x | x ∈ W, x + 2 < 9}
S = { 0,1,2,3,4,5,6}
Cordinal number of S
= n(S)
) = Number of elements in set S
= 7