Giant sets is the answer to your problem. Giant sets is a training method in which you do three or more exercises, one after the other, with no rest in between. The idea is to do a series of exercises in a row, take a brief rest period and then repeat the sequence for your desired number of sets. This is a good way to get an excellent workout done in a short amount of time (usually under 30 minutes).
I like to design my giant sets to hit the following major muscle groups; back, chest, and legs. I typically do 10 to 15 repetitions of each exercise for 3 complete sets with no more than 60 seconds rest between sets. Here's what one of my giant sets looks like:
- Back, lat pulldowns or seated low rows
- Chest, flat dumbbell presses or pushups
- Legs, barbell squats or walking lunges