Get out your stopwatches, read Dan Heisman's instructions before you begin, and play along! (Yes, I scored 12 out of 12, no, I wasn't as fast as I should have been, yes, I saw the dual solution. The easiest problem was the one that took me the longest.)
Here's an earlier Heisman quiz with the same format.
Thanks to Dan Heisman for pointing out that Chess Tactics for Students can be ordered directly from John Bain.