1. Which of the following is a well-defined set?
A a set of good writers
B a set of factors of 3
C a set of honest students in grade seven
D a set small numbers

2. Which of the following is the symbol of a null set?
A U
B Ո
C U- like letter c/ i can't search the symbol
D ø

3. michelle listed the set of all letters in the word 'serendipity' as shown below.what is wrong with this set?
A = {s,e,r,e,n,d,i,p,i,t,y}
A it uses commas
B it uses braces
C the objects in this set are not listed once
D a capital letter is used to represent this set

4. given the set of letters in the word "LOVE". what is the cardinality of the given set?
A 11
B 8
C 6
D 4

5. what is the cardinality of {10,20,30...,80}?
A 8
B 10
C 12
D 14​