Every minute on the minute do the reps of the primary exercise, then finish the minute with as many reps as possible of the secondary exercise.
Minute 1: 15 Pushups, then Plank
Minute 2: 20 Lunges, then Situp and Twist
Minute 3: 20 Jump Squats, then Flutter Kicks
Minute 4: 10 Burpees, then Mtn Climbers
Minute 5: Rest.