Hi Cyong
Of course you can do 1 set of each pose. Some studios offer this as a 60 minute class.
You can do whatever poses you like by stringing them together in any order. Have a Pranayama, Half Moon and then choose a number of standing poses, then a few floor poses and then a Savasana at the end. I put the 2 DVDs together with this in mind. There are classes of all different lengths with both single and double sets with a whole range from 25 minutes, to 30, 50, etc right through to the full 90. That wasn’t supposed to sound like an ad! 😉
Namaste
Gabrielle 🙂