Misc: which number system only uses 1 and 0?

Questions

Republic in southeastern Europe, bounded on the north by Austria, on the northeast by Hungary, on the south by Croatia, and on the west by Italy.?

Rhoda was a spinoff from what other popular tv show?

Rice what was lestat's mother's name?

Richmond is the capital of ______?

Rickenbacker who gave millions of dollars to britain in 1930?