((X/Y)*100)+Z = Ranking points

X= number of participants in the tournament
Y= your place finish
Z= Points for participating : 300 if you placed in the money. 200 if you did not place in the money.

Example 1
There were 17 participants and you finished in second place, in the money.
17/2 = 8.5
8.5*100 = 850
850+300 = 1150
Your ranking points for this tournament were 1150.

Example 2
There were 15 participants and you finished in sixth place, not in the money.
15/6 = 2.5
2.5*100 = 250
250+200 = 450

Your ranking points for this tournament were 450.