请教NN们！

(DI4) A sales manager's salary has two parts of commission, 20% of his sales amount and 10% of sales ammount of employee he supervisored. ask in January that manager's commission of the sales of his own.
1) Febuary the sales amount of his own and the employees under him increased 20% and 30%.
2) Febuary the sales amount if his own and the employees under him were N1 and N2 (forgot numbers)