If you're short on time combo exercises are the way to go. All you need is a set of dumbbells and ten minutes to get your heart revved with this quick workout.
1a. Alternating reverse lunge-curl to press: 3x6 each side
1b. Stiff legged deadlift: 3x10
1c. Wide stance squat with twist: 3x10
Perform one set of each exercise before rest. Take a quick 1 min break and repeat for all sets.