20% speak spanish how many students speak spanish?

You need to have the rest of the problem. This is incomplete. ;-;

You didn't add out of how many students is it like 20% out of 1000 then that can be solved but just 20% that could be any number. But if it's 20% out of 1000 then it's 800. But f not I don't know you need to finish writing the problem.  
  :/