We have a 'fifty-fifty' chance of succeeding. [=we are as likely to succeed as we are to fail]
The bill for dinner came to $43, and she gave him a 'fifty'.
They divided/split the expenses 'fifty-fifty'. [='equally']
(..) they might just save your life. Set your watch for ninety minutes. - Why ninety? Well, Houston clocked that debris at fifty thousand miles an hour. If you factor in our current orbit, then I figure we got about ninety minutes before we get our asses kicked again. O down to six percent. - Okay. (..)2013 Gravity