Theory of Sets

How do you the formal description for "a set containing all natural numbers that are greater than 5" ?

• { n | n ∈ N and n < 5 }

• { n | n ∈ N and n > 5 }

• { n | n ⊆ N and n > 5 }

• { n | n ⊂ N and n < 5 }

What does this statement means? A - B = { x | x ∈ A and x ∉ B }

• A union B, which consists of x, which is member of A or x is member of B

• A minus B, which consists of x, which is member of A and x is member of B

• A minus B, which consists of x, which is member of A and x is not member of B

• A minus B, which consists of x, which is member of A or x is member of B and x is
  not member of both A and B.

Let A be the set {x,y,z} and B be the set {x,y}. Is A a subset of B?

• True

• False

Let A be the set {x,y,z} and B be the set {x,y}. Is B a subset of A?

• True

• False

Let A be the set {x,y,z} and B be the set {x,y}. What is A ∪ B?

• {x,y,z}

• {x,y}

• {x}

• {y}

Let A be the set {x,y,z} and B be the set {x,y}. What is A ∩ B ?

• {x}

• {y}

• {x,y}

• {x.y.z}

Let A be the set {x,y,z} and B be the set {x,y}.

A x B = {(x,x), (x,y), (y,x), (y, y), (z, x), (z, y)}

• True

• False

Let A be the set {x,y,z} and B be the set {x,y}. What is he power set of B ?

• {∅}
  

• {{x,y}}

• {{x},{y},{x,y}}

• { ∅, {x},{y},{x,y}}

Let the universal set U = {0,1,2,3,4,5,6,7} and X = {2, 3, 4} and Y = {1, 4, 5}.

What is ( X ∪ Y ) ' ?

• {0,6,7}

• {1,2,3,4,5}

• {0,1,2,3,4,5,6,7}

• {∅}

Let X = {1,2,3} and Y = {0,2,4}.

What is X - Y (the complement of Y relative to X) ?

• {0,4}

• {0,1,3,4}

• {1,3}

• {0,1,2,3,4}