Sales tax

Hi there..I found this question in the kaplan kit

The following transactions took place during Alan’s first month of trading

(1) Credit Sales of $121 000 exclusive of sales tax
(2) Credit Purchases of $157 110 inclusive of sales tax
(3) Cash payments to credit supplier of $82710 inclusive of sales tax

Sales tax is 20%

What is the balance on Alan’s sales tax control account at the end of his first month of trading?

For this question we don’t include statement no (3) in the financial statements right
We don’t include it because the credit purchases already has an inclusive tax right???