mega

var preco = ["2.50", "17.50", "70.00", "210.00", "525.00", "1155.00", "2310.00", "4290.00", "7507.50", "12512.50"];

var min = [-1, 999999999999999], max = [-1, -1];

for (var quantNumb = 15; quantNumb != 5; quantNumb--) {

var max_comb = 60*59*58*57*56*55;

var no_repeat = 1;
for (var i = quantNumb; i > (quantNumb - 6); i--)
   no_repeat *= i;

var combs = Math.round(max_comb / no_repeat);
var payout= (combs * preco[quantNumb - 6]);
console.log(quantNumb + ": " + payout);

if (payout > max[1])
   max[1] = payout, max[0] = quantNumb;

if (payout < min[1])
   min[1] = payout, min[0] = quantNumb;
}

console.log("Pior: " + max[0]);
console.log("Melhor: " + min[0]);