There are six consecutive positive integers in Set S. What

Question

There are six consecutive positive integers in Set S. What is the value of positive integer n?

(1) When each integer in S is divided by n, the sum of remainders is 11.
(2) When each integer in S is divided by n, the remainders include five different values.

EvaJager · Answer

When dividing a positive integer by the positive integer  n , there are  n  possible remainders:
 0,1,2,...,n-1 .

(1) If  n=4 , the remainders are  0,1,2,3,0,1,2,3...  We can have a sequence of remainders  2,3,0,1,2,3  with a sum of  11. 
If  n = 5 , the remainders are  0,1,2,3,4,0,1,2,3,4,...  We can have a sequence of remainders  1,2,3,4,0,1  again with a sum of  11. 
Not sufficient.

(2) We have 6 numbers in our sequence and only 5 distinct remainders, so necessarily  n=5. 
And as we have seen above, the remainders  1,2,3,4,0,1  give the sum of  11. 
Sufficient.

Answer B.

corvinis · Answer

Thanks EvaJager. Understood

MathRevolution · Answer

Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.

There are six consecutive positive integers in Set S. What is the value of positive integer n?

(1) When each integer in S is divided by n, the sum of remainders is 11.
(2) When each integer in S is divided by n, the remainders include five different values.

The question states that the numbers are 6 consecutive terms, so we only need to know the first term; there is only one variable and 2 equations, so there is high chance that (D) will be the answer.
Looking at condition 1, for {1,2,3,4,5,6} and n=5, the sum of the remainder is 1+2+3+4+0+1=11, but for {2,3,4,5,6,7} and n=4, the sum of the remainder is also 2+3+0+1+2+3=11. n=4,5; no unique value of n is given, so this condition is insufficient.
Looking at condition 2, in order to have different remainders, n has to be 5. So the remainder becomes 0,1,2,3,4. This condition gives a unique value of n, so the answer becomes (B).

Normally for cases where we need 1 more equation, such as original conditions with 1 variable, or 2 variables and 1 equation, or 3 variables and 2 equations, we have 1 equation each in both 1) and 2). Therefore D has a high chance of being the answer, which is why we attempt to solve the question using 1) and 2) separately. Here, there is 59 % chance that D is the answer, while A or B has 38% chance. There is 3% chance that C or E is the answer for the case. Since D is most likely to be the answer according to DS definition, we solve the question assuming D would be our answer hence using 1) and 2) separately. Obviously there may be cases where the answer is A, B, C or E.

4MBA · Answer

Hi

B) if set S=0,1,2,3,4,5 then 5 will be the integer which gives the remainders include FIVE DIFFERENT VALUES
How about if S=1,2,3,4,5,6 then 6 too meet the criteria that is FIVE DIFFERENT VALUES
In the same manner 
2,3,4,5,6,7 - 7
3,4,5,6,7,8 - 8
Please clarify...?
Thanks in advance...

Posted from my mobile device

va789 · Answer

bb   VeritasKarishma   Bunuel  Other experts; please help

Bunuel · Answer

If S is {1, 2, 3, 4, 5, 6} and n = 6, then when each integer in S is divided by 6 we get the following remainders: 1, 2, 3, 4, 5, and 0, respectively. SIX different values.

If S is {2, 3, 4, 5, 6, 7} and n = 7, then when each integer in S is divided by 7 we get the following remainders: 2, 3, 4, 5, 6, and 0, respectively. SIX different values.

If S is {3, 4, 5, 6, 7, 8} and n = 8, then when each integer in S is divided by 8 we get the following remainders: 3, 4, 5, 6, 7, and 0, respectively. SIX different values.

Hope it's clear.

KarishmaB · Answer

Also, remember that when any positive integer is divided by n, the remainder can take one of n unique values (0 or 1 or 2 or ... or (n-1))

So when any positive integer is divided by 5, the remainder can take one of 5 values (0/1/2/3/4)
When any positive integer is divided by 6, the remainder can take one of 6 values (0/1/2/3/4/5)
and so on...

va789 · Answer

Thanks a lot for your reply. Yes, I understand this; thank you!

Rutvik15 · Answer

@  GMATNinja  Can you please explain this question?

There are six consecutive positive integers in Set S. What

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