1 - 1/2 + 1/3 - 1/4 + 1/5 - 1/6 + 1/7 - 1/8 + 1/9 - 1/10 = ?
How to get about this one?
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MBA.Aspirant
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GMATGuruNY
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1 - 1/2 = 1/2.MBA.Aspirant wrote:1 - 1/2 + 1/3 - 1/4 + 1/5 - 1/6 + 1/7 - 1/8 + 1/9 - 1/10 = ?
How to get about this one?
From there, the result will increase a little, decrease by less than it just increased, increase by less than it just decreased, decrease by less than it just increased, and so on.
Thus, every pair of terms after the first two terms will not affect the result very much.
Thus, the result will be a little more than 1/2.
The answer choices would dictate how precise we needed to be.
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Jayanth2689
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We can solve this by PEMDAS.
1 - (1/2 + 1/3) - (1/4 + 1/5) - (1/6 + 1/7) - (1/8 + 1/9) - 1/10 = ?
Addition first. Subtraction last.
so, 1 - (0.83) - (0.45) - (0.30) - (0.24) - 0.1
1 - 1.92 = - 0.92
Is this right?
1 - (1/2 + 1/3) - (1/4 + 1/5) - (1/6 + 1/7) - (1/8 + 1/9) - 1/10 = ?
Addition first. Subtraction last.
so, 1 - (0.83) - (0.45) - (0.30) - (0.24) - 0.1
1 - 1.92 = - 0.92
Is this right?
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MBA.Aspirant
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If you try the 2nd approach you'll find the result as 0.65. It's also easier cause you can cancel out the 0.1s with each other.
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abhishek.pati
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Hi Jaynath,...this is not correct asJayanth2689 wrote:We can solve this by PEMDAS.
1 - (1/2 + 1/3) - (1/4 + 1/5) - (1/6 + 1/7) - (1/8 + 1/9) - 1/10 = ?
Addition first. Subtraction last.
so, 1 - (0.83) - (0.45) - (0.30) - (0.24) - 0.1
1 - 1.92 = - 0.92
Is this right?
1 - (1/2 + 1/3) - (1/4 + 1/5) - (1/6 + 1/7) - (1/8 + 1/9) - 1/10 ......the equation which you have figured out has a flaw in it....
1 - (1/2 - 1/3) - (1/4 - 1/5) - (1/6 - 1/7) - (1/8 - 1/9) - 1/10.....this is the equation you must construct to get the right answer....hope it helps..!!
