Since Elodie has 30 rats, Hunter has 30 rats - 10 rats = <<30-10=20>>20 rats.
Together, Elodie and Hunter have 20 rats + 30 rats = <<20+30=50>>50 rats.
Kenia has three times as many rats as Hunter and Elodie have together, which is 3 * 50 rats = <<3*50=150>>150 rats
Together, the three have 150 rats + 50 rats = <<150+50=200>>200 rats.
#### 200