32. At least those responding corroborate your prediction. Could be self-selection. Those I got wrong I spent too much time analyzing, might have selected the "correct" answer if I had acted quicker. Does that corroborate Dunning-Kruger a bit?

EDIT: Reading further in the comments quite a few folks revealed a lower score. Actually that should not be too surprising, since some number of high-achieving, socially awkward types find fulfillment in hacking (Bill Gates).