This task is very simple to create. And so we do not create a tutorial for it. Below I have listed the steps, please try to do it like I did.
Steps to Like the certain photos with hashtag:
1. Add a Account module to select account to run.
2. Add a Text module to input your hashtag without this symbol # to search photos.
3. Add a Search Photos module to search photo by the hashtag you inputted on the Text module.
4. Add a Like module to like the searched out photos.
Btw, please take some time to watch the videos first before you create your own task. http://www.whitehatbox.com/bbs/BBSPost?postid=2502#.WG2nH338Y3A