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Is ab+c an odd integer, if a, b and c are positive integers? (1) c is
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10 Jul 2018, 19:32
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63% (01:01) correct 37% (01:03) wrong based on 70 sessions
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Is ab+c an odd integer, if a, b and c are positive integers? (1) c is odd. (2) Only one of the integers is even New question
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1) Absolute modulus : http://gmatclub.com/forum/absolutemodulusabetterunderstanding210849.html#p1622372 2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html 3) effects of arithmetic operations : https://gmatclub.com/forum/effectsofarithmeticoperationsonfractions269413.html
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Re: Is ab+c an odd integer, if a, b and c are positive integers? (1) c is
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10 Jul 2018, 19:59
chetan2u wrote: Is ab+c an odd integer, if a, b and c are positive integers?
(1) c is odd. (2) Only one of the integers is even
New question Given, a,b, and c are positive integers. Question stem:Is ab+c an odd integer? st1: c is odd So, when ab=Even , ab+c=Even+odd=Odd but, when ab=Odd, ab+c=Odd+odd=Even So, insufficient. st2:Only one of the integers is even when a=even & b,c=odd; ab+c=even+odd=odd when b=even & a,c=odd; ab+c=even+odd=odd when c=even & a,b=odd; ab+c=odd+even=odd So, sufficient. Ans. (B)
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Re: Is ab+c an odd integer, if a, b and c are positive integers? (1) c is
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11 Jul 2018, 00:03
chetan2u wrote: Is ab+c an odd integer, if a, b and c are positive integers?
(1) c is odd. (2) Only one of the integers is even
New question a,b,c > 0 Is (ab + c)  odd ? If ab  odd & c  even, then (ab + c)  odd If ab  even & c  odd, then (ab + c)  odd If ab  odd, then a  odd & b  odd If ab  even, then a or b or both  even Statement 1: c is odd ab can be odd or even & hence (ab + c) can be even or odd. Statement 1 alone is Not Sufficient. Statement 2: Only one of a, b, c is even If c  even, then ab  odd, hence (ab + c)  odd If b  even, then ab  even & c  odd, hence (ab + c)  odd If a  even, then ab  even & c  odd, hence (ab + c)  odd Statement 2 is Sufficient. Answer B. Thanks, GyM
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Re: Is ab+c an odd integer, if a, b and c are positive integers? (1) c is
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11 Jul 2018, 19:11
1. Not sufficient. We do not know anything about a and b
2. a or b even  even + odd = odd C even  odd + even = odd. Sufficient
Answer (B)
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Re: Is ab+c an odd integer, if a, b and c are positive integers? (1) c is
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06 Aug 2018, 07:03
chetan2u wrote: Is ab+c an odd integer, if a, b and c are positive integers?
(1) c is odd. (2) Only one of the integers is even
New question Hi chetan2u, Kindly provide the OA. It still displays a question mark(?) in my error log. Thanking you.
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Re: Is ab+c an odd integer, if a, b and c are positive integers? (1) c is
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07 Aug 2018, 13:48
chetan2u wrote: Is ab+c an odd integer, if a, b and c are positive integers?
(1) c is odd. (2) Only one of the integers is even
New question probable combination : a = odd b = odd c = even or a = odd / even b = odd / even c = odd. Note: odd + even = odd Statement 1 : c is odd. C could be odd . In this case ab has to be even. No information about a or b. NOT sufficient. Statement 2 : Among the 3 integers 1 is even. It means rest of the 2 are odd. It can be calculated as follows: If a = even , ab is even. C is odd. So, ab + c = odd. If c = even , ab is odd. Even + odd = odd. Sufficient. Thus the best answer is B.




Re: Is ab+c an odd integer, if a, b and c are positive integers? (1) c is &nbs
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07 Aug 2018, 13:48






