Explanation:
The journal entry to record the re-issuance of the stock is shown below:
Cash A/c Dr $240,000 (20,000 shares × $12)
Retained earnings A/c Dr $80,000
To Treasury stock $320,000
(Being the re-issuance of the stock is recorded)
The computation is shown below:
For treasury stock
= 20,000 shares × ($16 per share - $12 per share)
= $80,000
So as we can see the retained earnings is decreased by $80,000