Girls' Generation's YoonA and actor Jo Jung Suk attempted the 'bottle cap' challenge on 'Knowing Brothers'.

On the July 27th installment of the JTBC show, Jo Jung Suk expressed, "I'm by the book when it comes to acting, singing, and variety. I can do everything except for math." The 'Knowing Brothers' then said, "Do you want to be a world star?" and suggested Jo Jung Suk try the 'bottle cap' challenge trending on social media. 

YoonA also gave it a shot though she said nervously, "Is this how you do it?"

Find out how Jo Jung Suk and YoonA did in the clip above!