For each 6 minutes she performs, Carlotta spends 6 * 3 minutes = <<6*3=18>>18 minutes practicing.
For each 6 minutes she performs, Carlotta throws tantrums for 6 * 5 minutes = <<6*5=30>>30 minutes.
Thus, in total, for each 6 minutes of performance time, she spends 18 minutes + 30 minutes + 6 minutes = 54 minutes on all three activities.
#### 54