What comes next in the following series? 1/21, 1/14, 1/18, 1/16, 1/15, 1/18, 1/12, ......
[spoiler]OA= 1/20[/spoiler]
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AIM TO CRACK GMAT
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Brent@GMATPrepNow
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This would never be an actual GMAT question because it's possible to find more than 1 pattern in a set of numbers.AIM TO CRACK GMAT wrote:What comes next in the following series? 1/21, 1/14, 1/18, 1/16, 1/15, 1/18, 1/12, ......
[spoiler]OA= 1/20[/spoiler]
For example, what comes next in this sequence: 1, 2, 4, ... ?
Well, perhaps we're doubling each number, in which case the next value is 8
Or, perhaps we're adding 1, then 2, then 3 then 4 (etc), in which case the next value is 7
Likewise, for 1/21, 1/14, 1/18, 1/16, 1/15, 1/18, 1/12, ......, I could say that the correct answer is 3/17, because 1/21, 1/14, 1/18, 1/16, 1/15, 1/18, 1/12 are my 7 favorite fractions and 3/17 is my 8th favorite
Yes, I can see that having 7 values reduces the number of possible scenarios, but the rationale for why the GMAT would not test this still stands.
Cheers,
Brent
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ROHIT11111
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AIM TO CRACK GMAT wrote:What comes next in the following series? 1/21, 1/14, 1/18, 1/16, 1/15, 1/18, 1/12, ......
[/spoiler]
Notice that all the the numbers have 1 in the numerator, therefore answer will have 1 in the numerator.ROHIT11111 wrote:the answer is wrong as the answer is 1/20 ... can u let us know the soln.
Next find the factors of each number.
21 = 3 x 7
14 = 2 x 7
18 = 3 x 6
16 = 2 x 8
15 = 3 x 5
18 = 2 x 9
12 = 3 x 4
Notice that the first number in the red font is 3 and the other number starts at 7 and decreases by one.
Notice that the first number in the black font is 2 and the other number starts at 7 and increases by one.
Since the series go red,black,red, black.... the next number will be part of the black series which is 2 x (9+1) = 20
Since 1 is the numerator, the answer is 1/20
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HI AIM TO CRACK GMAT,
As Brent has pointed out, this is NOT representative of what you'll see on the GMAT. It looks more like a 'brainteaser' from some type of puzzle/math book. If you're actually studying for the GMAT, then you should focus on realistic (and reputable) GMAT practice resources.
GMAT assassins aren't born, they're made,
Rich
As Brent has pointed out, this is NOT representative of what you'll see on the GMAT. It looks more like a 'brainteaser' from some type of puzzle/math book. If you're actually studying for the GMAT, then you should focus on realistic (and reputable) GMAT practice resources.
GMAT assassins aren't born, they're made,
Rich
