Q2 and Q5 of Chater 15 income tax

Dear Sir,
Please help me to detail explain about the answer of question 2 and question 5 of Chater 15 income tax in Opentuition Practice question . There are 6 questions, I already answer for 4 questions.Remaining question 2 and 5 I can not undestand because the format of answer is difficlult to understand.

I am sorry not to post in the below of Practice question because I find some question posted here for long time ago but it has not been answerd,

I post question here with hope that you will see and answer.

Thank you so much.