Answer:
The amount of sales tax collected is $78.35
Step-by-step explanation:
Percentages
The gross receipts for the day were $1645.35, including a 5% sales tax.
If a percentage is already included (added) to a certain quantity, then it's not the original quantity or 100%.
The problem states that the gross receipts already include a 5% sales tax, thus the receipts are 100+5=105% of the net sales.
This means the net sales were $1645.35 / 105 * 100 = $1567
Subtracting $1645.35 - $1567 = $78.35 we get the amount of sales tax.
The amount of sales tax collected is $78.35
