There are 250 questions in TNPG. Each correct answer carried a mark of 0.36

There is no negative mark

So if you get all 250 correct, you get

250 x 0.36 = 90

The rest 10 are for what you call as experience marks, which can be 0 to 10 (never more than 10)

For every year after your CRRI, you get 1 mark. This is common for both service and non service. That is if you have completed your CRRI on or before 31.03.2007, you will get one mark in TNPG 2008. If you have completed CRRI on or before 31.03.2006, you will be getting 2 marks and so on. This is a maximum of 10 marks