Edit in JSFiddle

var percent = 33;
var answer;

switch (true){
  case (percent > 66.66 && percent <= 100):
    answer = '1';
    break;    
  case (percent > 33.33 && percent <= 66.66): 
    answer = '2';
    break;   
  case (percent > 0 && percent <= 33.33): 
    answer = '3';
    break;
}

console.log('Answer', answer);