Answer:
30%
Step-by-step explanation:
Tip: 4,2
Total cost: 32,2
Tip: (28×15)÷100 = 4,2
Total cost: Tip + original money
--> 4,2 + 28 = 32,2
30 copies.
Let's represent p as pages and c as copies
90p = 3 m
m = 90/3
m = 30