Dear Sir
Thanks for the answer by the way is there any way to slove my free item problem .

I want to make a decison table  in excel where my client will fill in  the item and free item list  as


Purchased ITem             No of purchase                 Free Item         No of free
==========================================================
Pen                                2                                     Rubber                 1
Pen                                5                                    Pencil                   1
Pen                               10                                   Pencil                   3
Pen                               12                                   Pencil                   4
Ink bottle                        3                                     Sticker                   1
Ink bottle                        5                                    Sticker                   2
Ink Bottle                       10                                     Sticker                  5


When a customer buys     19 pen then
his free item will be
4  pencil (due to first 12 pens)
5 pencil (due to remaining 5 pens)
1 rubber (due to  2 pens)

I have been trying to write the rule and fit into excel since from 1 week but due to my limited knowledge of drl and decision tables in excel it is taking a lot of time than writing code with lookup table and JAVA if else

Please help me to slove this riddle



Thanks
Niraj