katze.js

var prices = { x:15, y: 1, z: 0.25 };
var combinations = [];
for (var x = 1; x < 99; x++) {
  for (var y = 1; y < 99; y++) {
  	var z = 100 - x - y;
  	if (z > 0) {
  		combinations.push({x:x,y:y,z:z});
  	}
  }
}
var filtered = combinations.filter(function(element) { 
	return element.x * prices.x + element.y * prices.y + element.z * prices.z === 100;
});