Trip Tomorrow to Beijing from South Korea -US Passport

Hello,

I'm trying to make sure I understand this correctly. I'm hoping I can visit Beijing on 2/13 through 2/16 and do one of the two day tours your company offers. On 2/16 I planned to travel to Hong Kong, stay one day in Hong Kong and then back to the USA via Hong Kong to Chicago.

Will the 72 hour Visa work for my situation. Many thanks in advance :)!