Which of these sentences are propositions? What are the truth values of those that are propositions?
a) Boston is the capital of Massachusetts.
b) Miami is the capital of Florida.
c) 2 + 3 = 5.
d) 5 + 7 = 10.
e) x + 2 = 11.
f) Answer this question.
g) Do not pass go.
h) What time is it?
i) There are no black flies in Maine.
j) 4 + x = 5.
k) The moon is made of green cheese.
l) 2n ≥ 100