Write the set by listing their elements between braces

Write out the following sets by listing their elements between curly braces.
a. {x∈ℕ:x≤10
∈N:x≤10 and 3|x}.
b. {x∈ℕ:
∈N: is prime and 2|x}.
c. {x∈ℤ:x2=4
∈
Z
:
x
2
=
4
∈Z:x
2
=4}.
d. {x∈ℤ:x2=5
∈
Z
:
x
2
=
5
∈Z:x
2
=5}.
e. 2∅
2
∅
2
∅
.
f. {x∈ℤ:
∈
Z
:
∈Z: 10|x and x|100} .
g. {x:x⊆
⊆
⊆{1, 2, 3, 4, 5} and x$\leq$1}.

Answerboth technicians a and b are correct;