screenResolution = {
["0,5"] = {{15,36,57,79,100,121,143,164},{10,24,38,52,67,81}},
["1"]   = {{7,18,29,39,50,61,71,82},{5,12,19,26,33,40}},
["1,5"] = {{5,12,19,26,33,40,48,55},{3,8,13,17,22,27}},
["2"]   = {{4,9,14,20,25,30,36,41},{2,6,10,13,17,20}},
["2,5"] = {{3,7,11,16,20,24,29,33},{2,5,8,10,13,16}},
["3"]   = {{2,6,10,13,17,20,24,27},{2,4,6,9,11,13}},
["3,5"] = {{2,5,8,11,14,17,20,23},{1,3,5,7,10,12}},
["4"]   = {{2,5,7,10,13,15,18,21},{1,3,5,7,8,10}},
["4,5"] = {{2,4,6,9,11,13,16,18},{1,3,4,6,7,9}},
["5"]   = {{1,4,6,8,10,12,14,16},{1,2,4,5,7,8}},
}

local function getMonSize(x,y,scale)
   return screenResolution[scale][1][x],screenResolution[scale][2][y]
end
xValue, yValue = getMonSize(5,3,"1,5")
--Note: remember to put the quote on the scale value