The answer to the last puzzle was: 1. Bxg6+! Kxg6 2. Qa6+ Kh7 3. Qd3+ winning the hanging rook on b1
Puzzle #5 is quite nice. I've found it on Igor Smirnov's blog, in one of his free lessons. I couldn't resist the temptation to put it here too.
It is white's move. Try to calculate every variation to the end.
P.S. Here's the link to Smirnov's blog: http://gmsmirnov.com/#oid=1111_10