175. 18356-!-item-!-187;#058&011490 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 represents the simplified formula for computing the income tax, in Country R's currency, for a person in that country whose annual income is I ? a: 50+I/200 b:50+3I/100 c:50+I/40 d:100+I/50 E:100+3I/100 答案是c，画线部分的句子怎么理解呢？ | 
