So, no one helped me with my struggle with the question 6 of https://www.allaboutcircuits.com/worksheets/dc-branch-current-analysis/ and by some unknown for me reason even closed my thread on this topic https://forum.allaboutcircuits.com/threads/dc-brunch-current-method.205707/. And I came up with my own solution strategy that match with the answer. I will share it here for someone who struggle with this problem too.

 

Glad you got the right answer.

One thing that I strongly encourage you to start doing is to properly track your units throughout your work, instead of working with disembodied numbers and then tacking on whatever units you think, hope, and pray the final number should have.

You are going to make mistakes -- we all do -- and most mistakes will mess up the units, allowing you to immediately catch them and correct them before chasing a solution all the way to the end that is all-but-guaranteed to be wrong.