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

income tax是两部分的和　　

第一部分是个人年收入的2%

第二部分是个平均值　是“100(货币单位　例如元　角　分)”和“个人收入的1%”这两个东西的平均值

所以tax= 2%I + [(100 + 1%I)/2]=50+ I/40  选C