An odd number added to itself an odd number of times yields

Plug in some numbers and check -

3 + 3 + 3 = 9
5 + 5 + 5 + 5 + 5 = 25
7 + 7 + 7 + 7 + 7 + 7 + 7 = 49

Thus, the result will always be ODD, hence answer will be (A) an Odd Number.

The number property being checked is as follow:

1. Sum of two odd numbers is even
2. Sum of three odd numbers is odd.
3. Sum of four odd numbers is even

Conclusion: Sum of odd number of odd numbers is odd. While, sum of even number of odd numbers is even.
Example: Sum of 3 odd nos. is odd. Sum of 4 odd nos. is even

Confusion in the question, although GMAT may not test the language's dubiousness:

Consider an odd number 3: 3
Now, add 3 once to 3: 3 + 3 = 6, even
Now, add 3 twice to itself 3 + 3 + 3 = 9 odd.
Now, add t thrice to itself 3(the original number) + Three three [3 + 3 + 3\ = 12, even

So, as per the question's language, an odd number added odd number of times to itself will give an even number as a result. (The original property being; Sum of even number of odd numbers is even)

Shouldn't it be like odd number + odd number ( odd number of times)

3+3= 6
3+3+3+3 = 12

So B, an even number.

Rule 1: Sum of odd number of odd numbers (ie; sum of 3 odd numbers, sum of 5 odd numbers etc) is always odd.
Rule 2: Sum of even number of odd numbers (ie; sum of 2 odd numbers, sum of 4 odd numbers etc) is always even.

Therefore An odd number added to itself an odd number of times yields odd number.

To check this rule: Lets try

\(3 + 3 + 3 = 9\)

\(3 + 3 + 3 + 3 + 3 = 15\)

Answer (A)...

IMO, B

This is a tricky question just because it can be interpreted multiple ways.

Let's take 3

3 + 3 (added an odd # of times, in this case 1) = 6

3 + 3 + 3 + 3 (added 3 times) = 12

The red part is not in accordance with the condition stated in the question , you are adding an ODD number EVEN number of times....

Hope this helps..

The red part is not in accordance with the condition stated in the question , you are adding an ODD number EVEN number of times....

Hope this helps..[/b

Yea that's why I said this question is difficult bc it's hard to interpret. Is it added an odd number of times to the original number or overall added together an odd number of times?

Hopefully they wouldn't put such a question on the real test

[b]Posted from my mobile device

I really don't like how this question is worded. I feel like you could interpret it as 3 + 3 is adding three to itself ONCE.

This questions is worded incorrectly in my opinion if the answer is to be A.

If you add an odd number with itself 0 times, then the answer is just the odd number itself. Once you add the odd number with itself for the first time, it becomes even. Answer should be B IMO.

The wording of the question leaves room for interpretation. This is how I solved it:

1 added to itself 3 times is:

1 + 1 + 1 = 3

3 added to itself 5 times is:

3 + 3 + 3 + 3 + 3 = 15

Thus, we see the result must be an odd number.

Answer: A

IMO,

3 added three times to itself = 3+3+3+3

3 added three times = 3+3+3

the word itself must bring one more number in the calculation.

The wording of the question makes it possible to interpret it either way. For instance, from the sentence "3 is added to itself 3 times"; it is possible to understand that there are a total of three terms and also that we have the term 3 and we are adding three terms of 3 to that term.