Answer:
200
Explanation:
Let number of tickets sold before game be x while those at the gate be y
Total tickets sold are 600 hence x+y=600
Cost of tickets
Total amount collected is $700 hence
x+1.5y=700
x+y=600
x+1.5y=700
Subtracting equation 1 and 2
0.5y=100 hence y=200