Need !

which shows the elements of the set of whole number multiples of four less than 21?

a: {1, 2, 3, 4, 5}
b: {4, 8, 12, 16, 20}
c: all real numbers
d: null set

which shows the set(s) the number 2.77 is an element of?

a: real numbers

b: real numbers and natural numbers

c: natural numbers and whole numbers

d: null set

given sets:

d = {5, 6, 7, 8, 9, 10}, e = {1, 3, 5, 7, 9, 11}, f = {3, 6, 9, 12}

what is d n e?

a: {1, 3, 5, 6, 7, 8, 9, 10, 11}

b: {5, 7, 9}

c: {9}

d: null set

Which shows the elements of the set of whole number multiples of four less than 21?

The multiples of 4 are 4, 8, 12, 16, 20, 24, 28,...

Then, the set of the multiples of four less than 21 is {4, 8, 12, 16, 20}

A: {1, 2, 3, 4, 5}
B: {4, 8, 12, 16, 20}
C: all real numbers
D: null set

Which shows the set(s) the number 2.77 is an element of?

2.77 is a real number, it is not a natural number, and it is not a whole number.

A: real numbers

B: real numbers and natural numbers

C: natural numbers and whole numbers

D: null set

Given sets:

D = {5, 6, 7, 8, 9, 10}, E = {1, 3, 5, 7, 9, 11}, F = {3, 6, 9, 12}

What is D n E?

I believe the question is what is D ∩ E, which is the elements that are as much in D as in E. This is {5,7,9}

A: {1, 3, 5, 6, 7, 8, 9, 10, 11}

B: {5, 7, 9}

C: {9}

D: null set