Let's use algebra to solve the problem. Let x be the number of adult tickets, then the number of child tickets is 142 - x. The total revenue from adult tickets is 9.60x and the total revenue from child tickets is 5.30(142 - x). We know that the total revenue is $1113.80, so we can set up the equation:
9.60x + 5.30(142 - x) = 1113.80
Simplifying and solving for x, we get:
9.60x + 752.60 - 5.30x = 1113.80
4.30x = 361.20
x = 84
Therefore, 84 adult tickets were sold that day.