The total amount that Staci had in hand is $200.00.
The ticket at that time costs $87.96.
One Tshirt costs, $30.00.
Now that she has paid ticket, she will deduct the ticket from the cash she has in hand, so as to know the amount she is remaining with.
Tha is, $200-$87.96 = $112.04.
∴ In hand Staci has $112.04 extra cash whereby she can purchase more t shirts.
To get the number of tshirt she can buy, she will divide the amount she has in hand by the amount per piece of t shirt.
For example, $112.04 / $30 = $3.73.
∴ Staci can only purchase threet shirts only at a total cost of $90 for all the t shirts which is $30 × 3 = $90.
Staci has excess of 22.04 after deducting ticket and the other amount she has used to purchase the extra t shirts.
That is, $112.04 - $90 = $22.04.