jabhatta@umail.iu.edu wrote:
VeritasKarishma wrote:
jabhatta@umail.iu.edu wrote:
chetan2u VeritasKarishma Gladiator59 Bunuel generisHi Experts -- i see the answer is D in this question but i do have a question regarding "Estimating" this
Give estimation is a strategy for the GMAT -- i estimated :
1.0001 == estimated down to 1.0000
1.0003 == estimated down to 1.0000
Hence i was left with
\(\frac{0.99999999}{1}\) - \(\frac{0.99999991}{1}\) =
0.99999999 −0.99999991 =0.00000008 or 8 * \(10^{-8}\)
Question : why isn't the estimation method getting me close /somewhat close to option D ...option D seems 1000 times larger than my estimation (option B and option C sees closer)
Any idea where the logic is wrong in this case for such a HUGE difference ?
Note that all the numbers are very close to 1. So you cannot estimate some of them to 1 and not others. All options are very very close to each other too. So you cannot estimate here.
Hi
karishma Thank you so much for replying
Understand every answer is close to 1
But you would agree though the estimation method is OFF by times 1000 compared to option D
Any idea why the estimation is so off by any chance
I think every one would make the estimation that 1.0001 can be written up as 1.0000 and the same with 1.0003 as 1.0000
Posted from my mobile deviceNote that .99999999 is also almost 1. In fact it is closer to 1 than 1.0001. So if using approximation, the first fraction becomes 1/1 = 1. Same thing for second fraction. So if using approximation, you will get 1 -1 = 0. Note that every option is very close to 0.
The point is this:
You cannot say that 99/102 = 99/100 = .99
when your options have .99, .98. .97, .96, .95
Actually, the answer is .97 here. The margin of error is so small between the numbers and options that approximation will not give you the correct answer.
_________________
Karishma
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