We have [tex] \frac{5}{12} [/tex] of 252 people who have a personalized black disc
Number of people who would have personalized flying disc = [tex] \frac{5}{12}*252= \frac{2*252}{12}=105 [/tex] people
Then we work out the number of people who like to play disc golf:
[tex] \frac{25}{175}*105= \frac{25*105}{175}=15 [/tex] people
So we have 15 people who like to play disc golf and have personalised black disc.