JSFiddle - React, Tailwind, and code Playground
JavaScript
date = new Date();
today = date.getDay();
days = [7, 1, 2, 3, 4, 5, 6];
document.writeln('You\'ll only need to pay for ' + parseInt(today+1) + ' days since the week start on monday<br>');
document.write('The total amount will be 99+49+10.99/'+days[today]+')=$' + parseFloat(99 + 49 +10.99 / days[today]).toFixed(2))