tricky question please help

Let "x" be the fraction of the income Alice saves each month.
The fraction she does not save each month= 1-x.

Now total part of money saved in 12 months = 12x.
We are told that this amount is 3 times the money she does not save.
So 12x= 3(1-x)
=> 12x = 3-3x
=> x=1/5.

Hence D is the correct answer. The OA you have is incorrect.

Let me know if this works

grandh01 wrote:Alice's take-home pay last year was the same each month, and she saved the same fraction of her take-home pay each month. The total amount of money that she had saved at the end of the year was 3 times the amount of that portion of her monthly take-home pay that she did NOT save. If all money that she saved last year was from her take-home pay, what fraction of her take-home pay did she save each month?

1) 1/2
2) 1/3
3) 1/4
4) 1/5
5) 1/6

I understand the question but am not able to figure out how to come up with the answer.
Thanks in advance.

OA is C[/b]

An alternate approach is to plug in the answers, which represent the fraction saved each month.

Answer choice C: 1/4
Let the monthly pay = 4.
Amount saved each month = (1/4)4 = 1, so the amount not saved each month = 3.
Amount saved over the whole year = 12*1 = 12.
(Total saved)/(monthly not saved) = 12/3 = 4.
Since it is required that (total saved)/(monthly not saved) = 3, too high a fraction is being saved.
Eliminate A, B and C.

Answer choice D: 1/5
Let the monthly pay = 5.
Amount saved each month = (1/5)5 = 1, so the amount not saved each month = 4.
Amount saved over the whole year = 12*1 = 12.
(Total saved)/(monthly not saved) = 12/4 = 3.
Success!

The correct answer is D.