Find the set of interior points for each of these subsets of R (real #s).

(a) (-1, 1)

(b) (-1, 1]

(c) Q (rational #s)

(d) R - Q (irrational #s)

attempted answers:

(a) (-1, 1)

(b) (-1, 1)

(c) R - Q

(d) R - Q

I was just wondering whether or not these answers where correct or not.

Thanks