Answer:
They purchased 3 tickets for tier seats.
Step-by-step explanation:
From the information given, you can write the following equations:
x+y=12 (1)
45x+60y=585 (2), where
x is the number of tickets for floor seats
y is the number of tickets for tier seats
First, you can solve for x in (1):
x=12-y (3)
Next, you can replace (3) in (2):
45(12-y)+60y=585
540-45y+60y=585
15y=585-540
15y=45
y=45/15
y=3
Now, you can replace the value of y in (3) to find x:
x=12-3
x=9
According to this, the answer is that they purchased 3 tickets for tier seats.