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？

 to add (2 percent of one's annual income) to [the average of (100 units of

Country R's currency) and (1 percent of one's annual income)]