Hi.

Do not confuse the terms percentage and percentile.

Percentile Score is the score based on the relative performance of candidates who have appeared for the exam. To calculate a percentile score, the marks secured are converted into a scale ranging from 100 to 0 for each session of examinees.

NOTE : Percentile score is not the same as the percentage of marks secured.

So based on your marks, only percentage can be calculated which would be ((95+95+50)/300) 80%.

Good Luck