Guy's net income equals his gross income minus his

I think most people would agree that the answer lies in either E or C, at first glance some would propably pick C.
However, C is wrong since we need the ratio between gross income and deductions.

Assume that my gross income is 100 and my deductions is 100
With 1+2) income +4% = 4$ and deductions up 15% = 15$ which equals a net decline

If we change my income to 500 and keep deductions at 100
With 1+2) Income +4% = 20$ and deductions up 15% = 15$ which equals a net increase.

Conclusion, we need to know ratio/fraction of gross income to deductions to find the answer.

E.

Stat1 not sufficient to answer

Stat2 not sufficient to answe

Taking togethe also not sufficient, unless we know the actual amount.

Ans = E.
We do not know original Gross and Deduction amounts to find new values.

Thanks!!

Even I had reached to the conclusion that answer should be (E) but my reasoning was flawed.

Now I have understood the concept being tested over here!!

simple but tricky. +1 for the question. +1 for the answer.

thanks.

(n2-n1)/n1 is asked.
n1=g1-d1
n2=g2-d2
1) g2=1.04g1 Not Suff. as we do not know anything abt d1/d2
2) d2=1.15d1 Not Suff. as we do not know anything abt n1/n2
Cobining, (1.04g1-1.15d1-g1+d1)/(g1-d1)=(0.04g1-0.15d1)/(g1-d1) Still Not Suff. to calculate exact %.
So, E

I find it helps to write down the given relation:

Net Income = Gross Income - Deductions

Ques: By what % did Net Income increase if both Gross Income and Deductions increase?
First up, what comes to mind is that if both Gross Income and Deductions increase by the same percentage, Net Income will increase by the same % too.

Say, both increase by 10%,

New Net Income = (110/100)Gross Income - (110/100)Deductions
New Net Income = (110/100)(Gross Income - Deductions) = (110/100) Net Income

But here, even if we consider both statements together, we get
New Net Income = (104/100)Gross Income - (115/100)Deductions
There is no way we can find how New Net Income is related to Net Income. It will depend on the values of Gross Income and Deductions. (Take Gross Income as 100 and Deductions as 50 in one case and Deductions as 25 in another to see that Net Income changes by a different % in the two cases.)

Answer (E).
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Net income = NI
Gross Income = GI
Deductions = D
Changed Net income NIc
so, NI = GI - D
Required percentage = (NIc/NI)*100

(A) NIc = 1.04GI - D [Change of D is not given] Insufficient
(B) NIc = GI - 1.15D [Change of GI is not given] Insufficent

For C
NIc = 1.04GI - 1.15D [No way to remove GI and D to get only NIc] Insufficient.

Ans. E
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In questions like this, there has to be a relative information between the variables here they are I = G-D.

None of the options give this.Hence a clean E.

b]Guy's net income equals his gross income minus his deductions. By what percent did Guy's net income change on January 1, 1989, when both his gross income and his deductions increased?[/b]

Given: Net Income = Gross Income - Deductions.

(1) Guy's gross income increased by 4 percent on January 1, 1989. No info about deductions. Not sufficient.
(2) Guy's deductions increased by 15 percent on January 1, 1989. No info about gross income. Not sufficient.

(1)+(2) If Gross Income=100 and Deductions=100, then Guy had decrease in Net Income (since Deductions increased by greater percent than Gross Income) BUT if Gross Income=1,000 and Deductions=100, then Guy had some increase in Net Income. So, we cannot get the percent by which Guy's net income changed on January 1, 1989. Not sufficient.

Answer: E.

OPEN DISCUSSION OF THIS QUESTION IS HERE: guy-s-net-income-equals-his-gross-income-minus-his-deduction-139876.html
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