To upgrade a level 9 Palace to level 10 if you had no reductions you would need 2247131 building material. If you have a level 32 carpenter and 14% research reduction you need 1410989 building material. Now that is a 37.21% reduction. But a 32 level carpenter gives 32% reduction and research gives 14% reduction so you should be getting a 46% reduction in costs, which is 1213450 building material. I just know I am missing something here with the combined percentages but I can't seem to figure out what it is. Can anyone explain? Thanks.