24a+30b+40c+30d+40e+42f =24(a+d)+30(b+e)+40(c+f)+6d+10e+2f =2350+2(d+e+f)+4d+8e a+b+c<=50 (25-d)+(45-e)+(10-f)<=50 d+e+f>=30 24a+30b+40c+30d+40e+42f>=2350+60 24a+30b+40c+30d+40e+42f>=2410