If you have 10-15 minutes.....

Ok...first of all some of you are way over analyzing my workout routine. I do most of my workouts during my lunch. Sometimes i have an hour and sometimes 30-45 min. The reason why I still go to a gym on those short days is 1) to stay in the groove and 2) so I can change out of my dress clothes and be able to shower afterwards. Yes, in 10 minutes on the treadmill, in and incline, I can swat like a pig and need a shower. Most of my short days I can work out for 20 minutes but was unable to today. My question was do you do cardio or weights in a time crunch. Not to have people tell me I'm wasting my time. And, btw, I plan on walking outside tonight for almost an hour. If I'm paying for a gym membership I'm going to go there every chance I get. Thank you to those that answered with something I can work with in the future when I'm in a sudden time crunch.