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A, B, C and D are positive integers such that A/B = C/D. Is C divisibl
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16 Apr 2015, 04:46
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A, B, C and D are positive integers such that A/B = C/D. Is C divisible by 5? (1) A is divisible by 210 (2) B = 7^x, where x is a positive integer Kudos for a correct solution.
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Re: A, B, C and D are positive integers such that A/B = C/D. Is C divisibl
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16 Apr 2015, 05:08
Bunuel wrote: A, B, C and D are positive integers such that A/B = C/D. Is C divisible by 5?
(1) A is divisible by 210 (2) B = 7^x, where x is a positive integer
Kudos for a correct solution. 1. A could be 210 and B couuld be 10. C could be 42 and D could be 2. Not Sufficient 2. A could be 14 and B 2 A could be 140 and B 14 Not Sufficient 1 and 2: 210=2*3*5*7> A has atleast 1 factor of 5, which *if* not *divided away* by B will definitely be a value of C B is the exponent of 7. So the factor of 5 in the numerator is preserved. So C/D will *atleast* be 2*3*5=30. Hence, C will *atleast* be 2*3*5=30 Answer: C



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Re: A, B, C and D are positive integers such that A/B = C/D. Is C divisibl
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16 Apr 2015, 07:09
Bunuel wrote: A, B, C and D are positive integers such that A/B = C/D. Is C divisible by 5?
(1) A is divisible by 210 (2) B = 7^x, where x is a positive integer
Kudos for a correct solution. A*D/B = C (1) A is divisible by 210 A=2*3*5*7*K If B has one 5 then C may or may not have 5 , it depends on D. If B has no 5 then , yes, C will have 5 . Not Sufficient. (2) B = 7^x, where x is a positive integer we know B has 7(s) , we do not know about A and D . no sufficient. together : A has 5 and B does not have 5 so C will surely have one 5 . Answer C .



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A, B, C and D are positive integers such that A/B = C/D. Is C divisibl
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17 Apr 2015, 06:34
our question can be interpreted as \(\frac{A*D}{B} = 5*K\)? where K, A, D, B  integers #1 doesn't solve it coz B can be equal to A thus reducing the 210 completely and we are left with D which is unknown, INSUFFICIENT #2 actually makes it look abit different, our denominator consists of 7's and if our numerator is divisible by 5 then so is C, but otherwise (if A*D is not divisible by 5) C is not , INSUFFICIENT #1 + #2: combination of these makes our denominator a product of 7's which can't prevent number \(\frac{210*Z*D}{7^x}\) (A = 210*Z) from being divisibe by 5 due to number 210 alone being divisible by 5 and Z and D being positive integers thus giving us an explicit answer to the question. SUFFICIENT
C is the answer



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Re: A, B, C and D are positive integers such that A/B = C/D. Is C divisibl
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17 Apr 2015, 23:36
Given \(\frac {A}{B}\,=\,\frac {C}{D}\) \(C\,=\,\frac{A*D}{B}\)
Statement (i): A is divisible by 210 A \(=\,210\,*\,integer\); no info about either B or D Not sufficient
Statement (ii): B \(= 7^x\), where \(x\) is a positive integer; no info about either A or D Not sufficient
From (i) and (ii) C \(=\frac {30\,*\,7\,*\,integer\,*\,D}{7^x}\) \(\,\,\,\,\,= 30\,*\,some\,\,integer\); C is divisible by 5
Answer C



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A, B, C and D are positive integers such that A/B = C/D. Is C divisibl
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20 Apr 2015, 05:49
Bunuel wrote: A, B, C and D are positive integers such that A/B = C/D. Is C divisible by 5?
(1) A is divisible by 210 (2) B = 7^x, where x is a positive integer
Kudos for a correct solution. VERITAS PREP OFFICIAL SOLUTIONLet’s discuss the solution till the point I assume you will be quite comfortable. We need to find whether C is divisible by 5. So let’s separate the C out of the variables. C = AD/B Since C is an integer, AD will be divisible by B but what we don’t know is that after the division, is the quotient divisible by 5? Statement 1: A is divisible by 210 We still have no idea what B is so this statement alone is not sufficient. Let’s take an example of how the value of B could change our answer. Assume A is 210. If B is 3, AD/B will be divisible by 5. If B is 10, AD/B may not be divisible by 5 (depending on the value of D). Statement 2: B = 7^x, where x is a positive integer We have no idea what A and D are hence this statement alone is not sufficient. Using both together: Now, this is where the trick comes in. Using both statements together, we see that C = (210*a*D)/(7^x) Now we can say for sure that C will be divisible by 5.
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Re: A, B, C and D are positive integers such that A/B = C/D. Is C divisibl
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28 Jan 2016, 15:59
C=AD/B If we have at least one 5 as prime factor of C after the division the we can answer the question
Statement 1: We know that A has at least (2,3,5 and 7 as prime factors). But we do not know the value of B. INSUFFICIENT
Statement 2: We know that B has only 7 as prime factor, but we know nothing about the other numbers. INSUFFICIENT
Statements 1 and 2: Because we have 2, 3, 5 and 7 as prime factors of A*D and 7 is the only prime factor os B, we know for sure that we have at least one "5" as prime factor of C. SUFFICIENT



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Re: A, B, C and D are positive integers such that A/B = C/D. Is C divisibl
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16 Mar 2016, 06:12
Excellent Question here we just need to make sure that either A or D has one 5 and that B does not cancel that 5 => C
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Re: A, B, C and D are positive integers such that A/B = C/D. Is C divisibl
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Re: A, B, C and D are positive integers such that A/B = C/D. Is C divisibl
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