[qumo]

$(function() {
    var price = document.getElementById('answer'),
    ems_price = 2200;
    avia_price = 2500;
    sal_price = 2700;
    parohod_price = 1800;
    price.innerHTML = ems_price;
				
    function question() {
      var method = $('.find').val();
      switch(method) {
	case 'ems':
	var weight = +$('#weight').val();
	var sum = ems_price;
	if(weight >= 0.5 && weight <= 1){ // было weight => 0.5
	  for (var i= 50; i< weight*100; i++)  { //было var i = 5 и weight * 10
            sum += 20; // было sum += 200
	  };
	  price.innerHTML = sum;
        };
        if(weight >= 1.25 && weight <= 2){ //Добавил
          for (var i = 125; i< weight * 100; i++)  {
            sum += 24;
          };
          price.innerHTML = sum;
        }; //Конец добавленного
      break;
      case 'avia':
        price.innerHTML = avia_price;
      break;
      case 'sal':
        price.innerHTML = sal_price;
      break;
      case 'parohod':
        price.innerHTML = parohod_price;
      break;
    }
  }
  $('#weight').on("change", question);
  $('.find').on("change", question);
});