Megan Atwood 
Beat the Odds [EPUB ebook] 

The prize: $10 million The rules: Be the first to complete ten tasks assigned by the Benefactor. Do not ask questions. Do not tell anyone what you’re doing. Do not fail. The consequences: Unknown Ana has three choices: One, stay with her abusive foster parents and watch her little sister, Izzy, get hurt. Two, expose their abuse and risk being separated from Izzy. Or three, join the Contest, win the prize money, and escape together. No matter what Ana chooses, the odds are against her. But the Contest may turn out to be the most dangerous option of all.