Typo in exam question no 9 and question no 17. And need explanation of question number 24.

Question No 9: Shouldn't the vector a have been a row vector to have the question being correct? I will delete comment after clarification so that the question and answer of exam won't be available here.

Question No 17: Shouldn't the first vector have been a row vector to have the question being correct? I will delete comment after clarification so that the question and answer of exam won't be available here.

Question Number 24: Need  explation of why I am incorrect and explanation should be updated for everybody as this question doesn't contain explanation.