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If each term in an infinite sequence is found by the equation Sx=8x–6,
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03 Feb 2015, 09:42
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Re: If each term in an infinite sequence is found by the equation Sx=8x–6,
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04 Feb 2015, 01:04



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Re: If each term in an infinite sequence is found by the equation Sx=8x–6,
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Re: If each term in an infinite sequence is found by the equation Sx=8x–6,
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Updated on: 04 Feb 2015, 03:37
Bunuel wrote: If each term in an infinite sequence is found by the equation \(S_x=8^x6\), and \(S_1=2\), is every term in the sequence divisible by y?
(1) y is an even integer.
(2) At least 2 of the first 4 terms in the sequence are divisible by y.
Kudos for a correct solution. S(1)=2; \(S(2)=2^66\); \(S(3)=2^96\); \(S(4)=2^1^26\) Statement 1: if y = 2, 2, 0 then every term is a multiple of y. If y = 4 then S(1) becomes a proper fraction. Not sufficient. Statement 2: pick two random terms among those listed above. Each term is divisible by 2, 2, 1, 1, and a multiple of 0 and these values will be divisible by every other number in the senquence. Answer B. *Edited: added "a multiple of" before 0.
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Originally posted by gmat6nplus1 on 04 Feb 2015, 02:24.
Last edited by gmat6nplus1 on 04 Feb 2015, 03:37, edited 1 time in total.



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Re: If each term in an infinite sequence is found by the equation Sx=8x–6,
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Updated on: 04 Feb 2015, 03:25
Here we go:
S_x=8^x6, and S_1=2 (Given) St1: y is an even integer
Well the sequence will always be divisible by 2. but if we take y as 4 or 6, sequence will not be divisible Clearly not sufficient.
St2: At least 2 of the first 4 terms in the sequence are divisible by y.
we need to consider the first 4 terms, so better to find out the terms in order to be accurate..
First term = 2 (given) (X = 1) Second term = 58 = 2*29 Third term = 506 = 2*11*23 Fourth term = 4090 = 2*5*409
Randomly consider any 2 terms. Common factor : 1, 2, 1, and 2
Option B is correct
Originally posted by DesiGmat on 04 Feb 2015, 03:02.
Last edited by DesiGmat on 04 Feb 2015, 03:25, edited 2 times in total.



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Re: If each term in an infinite sequence is found by the equation Sx=8x–6,
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09 Feb 2015, 04:45
Bunuel wrote: If each term in an infinite sequence is found by the equation \(S_x=8^x6\), and \(S_1=2\), is every term in the sequence divisible by y?
(1) y is an even integer.
(2) At least 2 of the first 4 terms in the sequence are divisible by y.
Kudos for a correct solution. VERITAS PREP OFFICIAL SOLUTION:The correct response is (B). If you could determine the value of y, you could say whether every term in the sequence S is divisible by y. Start by expanding the sequence: 2, 58, 506, 4090,…etc. The only way that y can be a factor of ALL the terms is if y = 1 or y = 2. Statement (1) is not sufficient. If y = 2, then the answer is yes, but if y equals a different even number such as 4, then the answer is no. Statement (2) tells us that at minimum, two terms are divisible by y. If y = 1 or y = 2, then this holds true and the answer is yes. There is no other common factor of any two of 2, 58, 506, 4090…, etc, so y must equal either 1 or 2. Sufficient.
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Is every term in the sequence divisible by y
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20 Jan 2017, 20:54
If each term in an infinite sequence is found by the equation S(x)=8^x – 6, and S(1)=2, is every term in the sequence divisible by y?
(1) y is an even integer.
(2) At least 2 of the first 4 terms in the sequence are divisible by y.
(This is a question from Veristasprep. It gave me an explanation for the answer, but I still can't seem to understand the reasoning. Hoping someone can explain the answer. Thank you!!!!)



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Re: Is every term in the sequence divisible by y
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20 Jan 2017, 22:00
B.
S(1) = 2 S(2) = 58 = 2*29 S(3) = 8^3  6 = 2^9  6 = 506 = 2*11*23 S(4) = 8^4  6 = 2^12  6 = 4090 = 2*5*409
Statement 1: y is an even integer Y can be any one of 2,4,6,.......NOT SUFFICIENT
Statement 2: At least 2 of the first 4 terms in the sequence are divisible by y. The only common factor is 2. So, Y = 2. SUFFICIENT



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Re: Is every term in the sequence divisible by y
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21 Jan 2017, 03:23



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Re: If each term in an infinite sequence is found by the equation Sx=8x–6,
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