Question

can some one answer to this question
plse needed urgently

http://assets.openstudy.com/updates/attachments/515f3b0ee4b0115bc14d4d3b-msingh-1365195548569-untitled.png


why we have assume b=3 instead of 9

Answer 1

we can represent all of integers in the form\[z=3k\]\[z=3k+1\]\[z=3k+2\]u just evaluate \(z^3\) and see what are the results

Answer 2

i know the solution but one query arises in my mind that why in this question we have taken b-3

Answer 3

*b=3

Answer 4

u can also assume \[z=9k\]\[z=9k+1\]\[...\]\[z=9k+8\]but why doing such a heavy work?

Answer 5

and ok... lets think ..why we choose 3 ? :)

Answer 6

thats what the question itself dictates to u (i mean those 9m , 9m+1 and 9m+8) ...lets assume b=2...then u have\[z=2k \ \ \ \rightarrow \ \ \ z^3=8k^3\]\[z=2k+1 \ \ \ \rightarrow \ \ \ z^3=8k^3+12k^2+6k+1\]that will lead u to nothing...i hope im clear!!

Answer 7

i got it what u r saying
but there are so many simialr questions like these , in that we take the same digit
for example: 3m ,3m+1,3m+2
here we take b=3
or if there is 4m, 4m+1, 4m+2, we take b=4
but y here wet take b=3

Answer 8

that's exactly what i wannna ask

Answer 9

@SmoothMath