We have a proportion between prize points and raffle tickets: 1 price point per 5 raflle tickets.
We can use the rul of three to calculate how many prize points correspond to 405 raffle tickets:
"If 5 raffle tickets correspond to 1 prize point, then 405 raffle tickets correspond to x prize points"
NOTE: is useful to write and operate the units to check if the answer is correct.
Answer: 81 prize points.