Return lowest possible index position of second argument after it is added to the first arg's array and sorted...

sortAndAdd.js

function getIndexToIns(arr, num) {
  let numArr = arguments[0],
      addNum = arguments[1];
      numArr.push(addNum);
      numArr.sort(function(a, b) {
      return a - b;
  });
  return numArr.indexOf(addNum);
}

getIndexToIns([40, 60], 70);