Answer:
12000
Step-by-step explanation:
Sum the parts of the ratio, 5 + 2 = 7
Divide the total seats by 7 to find the value of one part of the ratio
42000 ÷ 7 = 6000 ← value of 1 part of the ratio
visiting fans = 2 × 6000 = 12000
8. You would take 48 (white tiles) then divide it by 6 to get 8. (Grey tiles)

The answer is above.
Additional note 1:

Additional note 2:
In the answer I filled in "0" at the place where "n" was. This is because the question tells us n=0