Closures Challenge

var calculateTotalWithTip = function (totalWithoutTip, tipPercentage) {
    let totalWithTip;
    function calculateTip(totalWithoutTip, tipPercentage) {
        let tipAmount = totalWithoutTip * tipPercentage;
        return tipAmount;
    }
    totalWithTip = calculateTip(totalWithoutTip, tipPercentage) + totalWithoutTip;
    return totalWithTip;
}

var tipAmount = calculateTotalWithTip(100, .20);
console.log(tipAmount);