What is the value of f(2) + f(4) + f(11) + f(12) for the function f ?
$straight f left parenthesis straight x right parenthesis space equals space open curly brackets table attributes columnspacing 1em end attributes row cell 100 space comma space 0 space less than space straight x space less or equal than space 4 end cell row cell 95 space comma space 4 space less than space straight x space less or equal than space 8 end cell row cell 90 space comma space 8 space less than space straight x space less or equal than space 12 end cell row cell 95 space comma space 12 space less than space straight x space less or equal than space 16 end cell end table close$

30
280
290
380

hint Hint: