请教PP3上的一题，没看懂啊

dada1023

Before being simplified, the instruction 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

哪位仁兄或者神仙JJ帮个忙啊？

yuanchenqin

收入为I， 就是把收入的2%（2I/100=I/50)加到100和收入的1%（I/100）的算术平均数中去，即50+I/50+I/200=50+I/40