Problem definition:
Given your balance, pick a subset of upgrades such that summation of Power, Traction and Aerodynamics are maximized and summation of costs doesn’t exceed balance. Problem can be found on this page: http://apps.facebook.com/motorcycle_madness/upgrade.php
Solution:
We will use linear programming method. Let’s use an example here. For the initial problem:
Balance: $73,845
Upgrades available: