PanCar

$('#but').click(function() {
    let arr = [
    {
    name: "Apple",
    chance: 20
  },
  {
    name: "Banana",
    chance: 40
  },
  {
    name: "Knife",
    chance: 40
  }
];

console.log(fillArray(arr)[rand100()]);

function rand100() {
  return Math.floor(Math.random() * Math.floor(100));
}
function fillArray(data) {
    let arr = [];
  data.forEach(el => {
        for (let i = 0; i < el.chance; i++) arr.push(el.name);
    });
  return arr;
}
});