Shadow Form Recharge

Prolly has been asked before, but meh, every now and then, a seasoned Guru'r can "noob" away and ask a bold question:

What's the EXACT recharge (in seconds, and .X seconds) of Shadow Form when reduced with Deadly Paradox and Glyph of Swiftness?

I COULD chronotime it, I COULD use some kind of program that calculates the time, but I'm not in a hurry, and in a lazy mood.

My best gues would be they DON'T add up 33% + 25%, but rather multiply. I don't know, I just want to know the recharge.

(It's somewhere between 20 and 30 seconds )

Thanks in advance

Skill recharge benefits stack up to 50% unless a single skill goes past that limit. Also, percentage skill effects do multiply as you presumed. Glyph of Swiftness and Deadly Paradox will multiply together to make 49.75% reduction in recharge, which results in a 22.6125 second recharge.

tl;dr version - 22.6 seconds.