UmangMathur wrote:This seems to be an oral question...

8*10^k + j

8 multiplied by any power of 10 (0 - infinity) will always give remainder 8 when divided by 9

thus in this case, it's the value of j that will determine the remainder and not the value of k. Rather, the equation is independent of k.

Thus we can determine the value, just by having the value of j.

Thus the choice is B

:twisted:

Nice.

Once we've rephrased the target question as, "What is the value of j?", we can see that the correct answer must be B.

Cheers,
Brent

[email protected] wrote:answer is 8

The answer is 8?

Cheers,
Brent

cuddytime wrote:Could we have the question modified as follows to clear any confusion?

(8*10^k)+ J?

The old question still followed orders of operation, but I have changed it nonetheless.

Cheers,
Brent

Shubhu@MBA wrote:8*10^k + j when divided by 9 will always give a remainder of 8(provided k & j are both positive integers)

Thus this question can be answered by any of the options given in the question

I think you're reading the expression as 8 * 10^(k+j) in which case you're right; the remainder will always be 8
However, the expression is actually meant to be 8*(10^k)+j, in which case the remainder varies, depending solely on the value of j.

Cheers,
Brent

Shubhu@MBA wrote:

Brent@GMATPrepNow wrote:

Shubhu@MBA wrote:8*10^k + j when divided by 9 will always give a remainder of 8(provided k & j are both positive integers)

Thus this question can be answered by any of the options given in the question

I think you're reading the expression as 8 * 10^(k+j) in which case you're right; the remainder will always be 8
However, the expression is actually meant to be 8*(10^k)+j, in which case the remainder varies, depending solely on the value of j.

Cheers,
Brent

Thanks for the clarification.

(8 * 10^k )/9 will always leave a remainder 8.

Thus, it is "j" which will determine what the the remainder will be for the expression 8*(10^k)+j.

Hence Option B will be the answer.

If J=1 then the remainder for above expression will always be 0, as the expression will always be completely divided by 9, no matter what is the value of K.

Exactly.

Cheers,
Brent

pablo_vish wrote:Hi Brent,
Nice question.. I was able to get this one quickly thanks to your online course..
Was just wondering, whether it would be fine to solve this by choosing numbers and then applying the divisibility rule?

Thanks for the feedback, Pablo

We can choose numbers for statement 1 to show that it is not sufficient.
When we choose numbers for statement 2, we can't definitively show that the statement is sufficient, but with each set of numbers, we can gain more confidence that it is, indeed, sufficient.

If anyone would like to learn more about choosing numbers (and using a table to organize your information), you can watch the following free video: https://www.gmatprepnow.com/module/gmat- ... cy?id=1101

Cheers,
Brent