题目是 Before being simplified, the instructions for computing income tax in Country R were to add 2 percent of one's annual income to the average (arithmetic mean) of 100 units of Country R's currency and 1 percent of one's annual income
Which of the following reprentes the simplified formula for computing the income tax, in Country R's currency, for a person in that Country whose annual income is I?
答案是 50+ I/40 关键是我不太理解 to add 2 percent of one's annual income to the average (arithmetic mean) of 100 units of Country R's currency 的意思，请NN帮忙，谢谢！ | 
