Discrete Mathematics?

Question

Choose the appropriate sign to fill in the blanks

{x | x N and x > 7} ___ {x | x N and 2 < x 7}

I have to choose from answers.

1. is a side ways U with a ___ underneath it and a / through the U.

2. is a side ways U with a ___ underneath it

3. is a side ways U and a side ways U with a ___ underneath it

4. is a side ways U

The other question is :

1. Express the set {x | x is an integer greater than -4} in roster form

a. { -3, -2, -1, . . .}

b. { -3, -2, -1, 0}

c. { -5, -6, -7}

d. { -5, -6, -7, . . .}

Determine the number of subsets of {1, 2, 3, ..., 6} (Points: 4)

64

128

60

16

Not sure how to do these problems. I think the second question is B and the 3rd question is 64. Can anyone help me out on these?

Answer 1

I wonder? Does discrete mathematics have anything to do with a discrete metric space?

M is a metric space.

M = (X,d) where d is the metric or distance function

d(x,y) = { 1 (if x not equal y); 0 (if x=x)}

Answer 2

Your first question is not clear. What is &#039;2 &lt; x 7&#039;? And you should use the options is a subset of, is a proper subset of, is not a subset of, etc.

2nd one is not b. It can take all the positive integers too.

3rd one is correct.

Answer 3

1. a

2. 2^6

Answer 4

1. Express the set {x | x is an integer greater than -4} in roster form

a. { -3, -2, -1, . . .}

b. { -3, -2, -1, 0}

c. { -5, -6, -7}

d. { -5, -6, -7, . . .}

the answer is a. { -3, -2, -1, . . .}

Determine the number of subsets of {1, 2, 3, ..., 6} (Points: 4)

64

128

60

16

The number of the elements of the given set, say A,

n(A)=6

The number of the subsets is 2^n,  that is

2^6=2.2.2.2.2.2=64

the answer is 64