Question

Write formal descriptions of the following sets.

(a) The set containing the numbers 1, 10, and 100
(b) The set containing all integers that are greater than 10
(c) The set containing all natural numbers that are less than 10
(d) The set containing nothing at all
(e) The set containing the empty string
(f) The set containing the string abc

Answer 1

{1, 10, 100}

{a : a ∈ Z and a > 10}

{a : a ∈ N and a < 10}

∅

{ε}

{abc}

Step-by-step explanation:

1.) A set containing the numbers 1, 10 and 100

2.) Z represents integers, hence numbers n the set are integers values greater Than 100

3.) N represents natural numbers, this the set contains natural numbers less Than 10

4.)∅ represents a null or empty set

5.)represents an empty string

6) contains the sting values a, b and c