Couple set questions..

1.) Given:

{x | x = k^2, k=1,2,3,...,100}, determine the cardinal #.

I said it would be 100, as you'd have 100 numbers.

2.) Suppose D is a proper subset of E;

Determine the least possible # of elements that are in D.

I'm assuming this is 1?

3.) If D is a subset of E, are we able to say D is a proper subset of E?

I'd say NO but my example I tried given contradicted itself.