Data Sufficiency

I came across the following in a practice test that i am struggling to solve. Can anyone help please?

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

As per the question - " 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."

1st part - 2 percent of one's annual income
If I denotes income then 2/100* I = I/50


2nd part - average (arithmetic mean) of 100 units of Country R's currency and 1 percent of one's annual income
implies - ( 100 + (1/100*I)) / 2
= 100/2 + I/200
= 50 + I/200

Adding first and second part, we get 50 + I/40

Answer is C

Thanks so much. You made it look really simple.