In Q-9 how can sundry debtor be 7400 it is written 9600

Dear Student, it seems to us that you have some misunderstanding. In our solution the amount of Sundry Debtors and Sundry Creditors has been rightly written as Rs 7,400 and Rs 9,600 respectively. Therefore, it is absolutely correct.
We advice you re-check you query. If you find any difficulty, you may get back to us. We assure you our help.