Answer:498 movie tickets were sold.
Explanation:
Let x represent the number of movie tickets that were sold.
Let y represent the number of popcorns that were sold.
A total of 608 movie tickets and popcorn were sold. It means that
x + y = 608
A movie ticket cost $11 and popcorn cost $4.20. The theater manager calculated the total revenue for the night to be $5940. It means that
11x + 4.2y = 5940- - - - - - - - - -1
Substituting x = 608 - y into equation 1, it becomes
11(608 - y) + 4.2y = 5940
6688 - 11y + 4.2y = 5940
- 11y + 4.2y = 5940 - 6688
- 6.8y = - 748
y = - 748/- 6.8
y = 110
x = 608 - y = 608 - 110
x = 498