everyone here seems to be at loose ends atleast where costing is concerned....i refered to the compiler totally...solved it 3 times ...theory u need to stress on...i did that from compiler as well...and for OR,again compiler was my best friend...i got 57 in costing..solve the questions without looking at the answers...and when solving try not to get distracted..that way u will learn to solve fast..i didnt take any tution for any subject btw..