The Texan says yes and asks the bartender to line up 10 pints of Guinness.
Immediately the Irishman tears into all 10 of the pint glasses drinking them all back-to-back.
The other pub patrons cheer as the Texan sits in amazement.
The Texan gives the Irishman the $500 and says,
“If ya don’t mind me askin’, where did you go for that 30 minutes you were gone?”
The Irishman replies,
“Oh…I had to go to the pub down the street to see if I could do it first”.