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Director
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What is the remainder when the positive integer n is divided [#permalink]
 10 May 2009, 21:09
Question Stats:
25% (02:32) correct
75% (00:52) wrong based on 2 sessions
What is the remainder when the positive integer n is divided by 2?
(1) When n is divided by 5, the remainder is an odd integer.
(2) When n is divided by 10, the remainder is an odd integer.
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Director
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reply2spg wrote: What is the remainder when the positive integer n is divided by 2?
(1) When n is divided by 5, the remainder is an odd integer.
(2) When n is divided by 10, the remainder is an odd integer. (1) Let n = 8, remainder 3.....so, 8/2 = remainder = 0 Let n = 16, remainder 1....so 16/2 = remainder = 0 Suff (2) n = can be 10,30,50,70,90,110,130 etc All these numbers are divisible by 2, remainder = 0 Suff D P.S > I hope i'm not missing something
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SVP
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I think its B.
From stat 1, n could be 6 or 11. Both numbers give different remainders when divided by 2.Insuff.
From stat 2, n can be 11, 21, 31, etc. In all cases, it gives a remainder of 1 when divided by 2. Suff.
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Director
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n is +ive int, rem when n/2?
1)n/5, rem is odd
test numbers 13,21,28
13/2 rem=1, 21/2 rem=1, 28/2 rem=0, insuff
2)n/10, rem is odd
test numbers 13, 21, 27
13/2 rem=1, 21/2 rem=1, 27/2 rem =1, suff
B
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Director
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bigtreezl wrote: 1)n/5, rem is odd
test numbers 13,21,28
13/2 rem=1, 21/2 rem=1, 28/2 rem=0, insuff
B I knew I was missing something.
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GMAT Instructor
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reply2spg wrote: What is the remainder when the positive integer n is divided by 2?
(1) When n is divided by 5, the remainder is an odd integer.
(2) When n is divided by 10, the remainder is an odd integer. Without testing numbers: First, there are only two remainders possible when you divide n by 2: 0 and 1. The remainder is 0 if n is even, and 1 if n is odd. So the question is really just asking "is n odd?" Remember the quotient/remainder definition. When we divide n by d, we have n = qd + r, where r is the remainder and q the quotient. From S1, n = 5q + r, where r is odd. So n = 5q + odd, and n could be even if q is odd, and n could be odd if q is even. Insufficient. From S2, n = 10q + r where r is odd. So n = even + odd = odd. Sufficient.
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IanStewart wrote: reply2spg wrote: What is the remainder when the positive integer n is divided by 2?
(1) When n is divided by 5, the remainder is an odd integer.
(2) When n is divided by 10, the remainder is an odd integer. Without testing numbers: First, there are only two remainders possible when you divide n by 2: 0 and 1. The remainder is 0 if n is even, and 1 if n is odd. So the question is really just asking "is n odd?" Remember the quotient/remainder definition. When we divide n by d, we have n = qd + r, where r is the remainder and q the quotient. From S1, n = 5q + r, where r is odd. So n = 5q + odd, and n could be even if q is odd, and n could be odd if q is even. Insufficient. From S2, n = 10q + r where r is odd. So n = even + odd = odd. Sufficient. Really really love any thorough explaination like this. Thanks IanStewart
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1) n = 5q + odd
^This doesn't tell us whether q is divisible by 2 or not. So this info is insufficient.
2) n = 10q + odd,
= 2(5q) + odd
^We can see that the remainder is odd. So this info is sufficient. B
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Director
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Very nicely explained, thanks Ian IanStewart wrote: reply2spg wrote: What is the remainder when the positive integer n is divided by 2?
(1) When n is divided by 5, the remainder is an odd integer.
(2) When n is divided by 10, the remainder is an odd integer. Without testing numbers: First, there are only two remainders possible when you divide n by 2: 0 and 1. The remainder is 0 if n is even, and 1 if n is odd. So the question is really just asking "is n odd?" Remember the quotient/remainder definition. When we divide n by d, we have n = qd + r, where r is the remainder and q the quotient. From S1, n = 5q + r, where r is odd. So n = 5q + odd, and n could be even if q is odd, and n could be odd if q is even. Insufficient. From S2, n = 10q + r where r is odd. So n = even + odd = odd. Sufficient. |
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Yeah B
(1)Gives n=odd and even both
(2)Gives n=odd
Therefore,B is correct.
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sondenso wrote: IanStewart wrote: reply2spg wrote: What is the remainder when the positive integer n is divided by 2?
(1) When n is divided by 5, the remainder is an odd integer.
(2) When n is divided by 10, the remainder is an odd integer. Without testing numbers: First, there are only two remainders possible when you divide n by 2: 0 and 1. The remainder is 0 if n is even, and 1 if n is odd. So the question is really just asking "is n odd?" Remember the quotient/remainder definition. When we divide n by d, we have n = qd + r, where r is the remainder and q the quotient. From S1, n = 5q + r, where r is odd. So n = 5q + odd, and n could be even if q is odd, and n could be odd if q is even. Insufficient. From S2, n = 10q + r where r is odd. So n = even + odd = odd. Sufficient. Really really love any thorough explaination like this. Thanks IanStewart Very Good Explanation.
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Ans is B
As per statement one the number can be either odd or even. but when u divide by 10 you will get odd integer only when you divide a odd integer
So Ans is B
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