GMAT PREP-Someone please help me with this math questionv2

[Guest]

Another one.. For this one I do not understand the wording of the question. Please someone help me understand

Before being simplified, the instruction for computing income tax in Country R were to add 2% of one's annual income to the average (arimethic mean) of 100 units of Country R's currency and 1% 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)

Answer: C

Please let me know how you get C as the answer. Thanks

SB

[StaceyKoprince]

Please read (and follow!) the guidelines in the stickies. GMATPrep problems have their own folders. Also, your subject line should be the first 5-8 words of the problem itself. I'll move this over to the right folder for you this time but please remember for next time! Thanks. :)

[DaveGill]

2% of income (I) = (2/100)I

1% of income (I) = (1/100)I
100 units of R's currency = 100
Average of 100 units of R's currency and 1% of I = [100+(1/100)I]/2

Average added to 2% of I = (2/100)I+[50+(1/200)I]

and simplify to get:

50 + (I/40)

Answer is C.

[RonPurewal]

well played.

i wanted to fill in the following hole, which might be problematic for some to follow (especially given the format here, which, to say the least, is not ideal for typing fractional expressions):

Average of 100 units of R's currency and 1% of I = [100+(1/100)I]/2

Average added to 2% of I = (2/100)I+[50+(1/200)I]

the quantity [100+(1/100)I]/2 in the first problem has been simplified to [50+(1/200)I], the right-hand part of the second expression.

[GuilhermeM789]

Please, would some of you help me further with that one?

I skipped this question during the GMAT PREP test because there is one thing that didn't make sense to me. The question starts with "Before being simplified..." then describes how the calculation was done before the mentioned simplification. So, as far as I got, we were provided with a description of the non-simplified way of computing income tax. But, the question asks us about the "simplified formula".

Well, that still doesn't make sense to me.
So, please, would some of you Manhattan Prep instructors help me to understand how this question really works in terms of the "simplified formula" versus the formula "before being simplified"?

Thank you!!!

[RonPurewal]

"simplified", here, just refers to the algebraic simplification.

i mean, let's say that X is your height in inches, and i tell you: "add your height, in inches, to itself."
ok, that's X + X.
X + X is an UNSIMPLIFIED formula.
after this is simplified, it's 2X.

does that make sense?
do you see the analogy here?

[GuilhermeM789]

Hi Ron,

Thanks for the explanation. Yes, it makes sense, sure.
Wow, it is amazing how the GMAT sometimes just throws people away from the real question in unexpected ways.

Thank you!

[RonPurewal]

that has nothing to do with "throwing people away from the question".

the words mean exactly what they say, and the words say exactly what they mean. you just have to read the words very, very literally.
remember—there are NEVER any "tricks" on this exam. never ever ever ever.