Information relating to Lauren Co's transactions for the month of May 20X4 is shown below：
$
Sales (including sales tax) 140,000*
Purchases (net of sales tax) 65,000
Sales tax is charged at a flat rate of 20%. Lauren Co's sales tax account had a zero balance at the beginning of the month and at the end of the month.
* Lauren Co's sales for the month of $140,000 included $20,000 of sales exempt from sales tax. What was the total sales tax paid to regulatory authorities at the end of May 20X4 (to the nearest $)?