# Math Help - real number problem 2

1. ## real number problem 2

prove that if a positive integer is of the form 6q + 5 then it is in the form 3 q + 2 for some integer q but not conversely.

2. Originally Posted by saha.subham
prove that if a positive integer is of the form 6q + 5 then it is in the form 3 q + 2 for some integer q but not conversely.
This one is easy.
$6q+5=3(2q+1)+2$.

The number 2 is the counterexample needed in the second part.

3. plzz explain a bit more the part two

4. Originally Posted by saha.subham
plzz explain a bit more the part two
2=3.0+2, so it is of the form 3q+2 (take q=0).

2 is not of the form 6q+5.
If it were, then
2=6q+5
3=6q
q=-1/2, which is not an integer.