Suppose 100 students in your school participate in a math olympiad of 50 marks. The results are declared and your percentage is 96 where as percentile is 90. What does it mean ?

96% ⇒ You answered 48 correct out of 50 [(48/50)× 100 = 96%]

90th percentile ⇒ 90% of the students got same marks as you or less (≤ 48); and 10% of the students scored more than you(≥ 48 i.e. 49 or 50).

Lets look at an hypothetical situation. What would be your percentile if all the other 99 students scored more than you ?

his is despite you having a very high percentage of 96.
That is the difference between percentage and percentile.