Is the sum of a series of n consecutive integers even?
(1) n=6
(2) The n digit number formed by the seriest is a multiple of nine
OA after some discussion.
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Sum of consecutive integers
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Frankenstein
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Hi,
From(1):
Sum of integers from a to (a+5) = 6a+15. This is always odd.
Sufficient
From(2):
if the number is 45, sum is odd
if the number is 3456, sum is even
Not sufficient
Hence, A
From(1):
Sum of integers from a to (a+5) = 6a+15. This is always odd.
Sufficient
From(2):
if the number is 45, sum is odd
if the number is 3456, sum is even
Not sufficient
Hence, A
Cheers!
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Things are not what they appear to be... nor are they otherwise
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saketk
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Condition 1- any 6 consecutive integers will contain 3 odd and 3 even = resultant will always be ODD.GmatKiss wrote:Is the sum of a series of n consecutive integers even?
(1) n=6
(2) The n digit number formed by the seriest is a multiple of nine
OA after some discussion.
Sufficient
Condition 2 -- Consider 11+12+13 = 36 -even
Consider 2+3+4+5+6+7 = 27 -- ODD...
Not sufficient.
Hence answer = A
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Frankenstein
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Hi,saketk wrote: Condition 2 -- Consider 11+12+13 = 36 -even
Consider 2+3+4+5+6+7 = 27 -- ODD...
Not sufficient.
Hence answer = A
Minor mistake. You cannot choose 11,12,13. If you are choosing this set, you are picking n as 3.
When we write those numbers in a series it becomes 111213, which is not 'n' digit number.
We can only pick single digit numbers.
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Frankenstein
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Yes, but not directly. If the n consecutive integers are 2,3,4,5,6,7.. then 234567(6- digit number) is divisible by 9. Anyway for a number to be divisible by 9, the sum of its digits should be divisible by 9. So, we can interpret that it says sum of digits is divisible by 9 , but the consecutive numbers chosen should be single digit ones to make the series 'n'- digit number.AVbyT wrote:I didn't understand statement 2. Does it mean that the sum of the n consecutive integers is a multiple of 9?
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sl750
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Statement 1
n=6
Sum of an even number of consecutive integers is odd when we have an odd number of integers in the sequence, as we have 3 odd and 3 even numbers. The sum is Odd. Sufficient
Statement 2
Depending on whether n is even or odd, the sum of multiples of 9 could be odd/even or even/odd. Insufficient
n=6
Sum of an even number of consecutive integers is odd when we have an odd number of integers in the sequence, as we have 3 odd and 3 even numbers. The sum is Odd. Sufficient
Statement 2
Depending on whether n is even or odd, the sum of multiples of 9 could be odd/even or even/odd. Insufficient
