Show that $$\frac{1}{n+1}+\frac{1}{n+2}+...+\frac{1}{3n+1}>1,\:\forall n\in\mathbb{N}$$
This is a 9th grade problem.
I was trying to take the greatest numerator, which is the last numerator of the last fraction. But there are only $2n+1$ terms. Right?
After that I have no idea. Thx!
achille hui's solution seems rather elegant. I would be tempted to suggest merging so that it is more visible. (I'd prefer this answer on the copy of the question which remains open.)
@MartinR It's probably a stretch. You see who added the tag - it's quite possible that changes would lead to yet another editing/retagging war.
I do not know if this problem has already been addressed in number theory known with another name, but I have been some time unsuccesfully trying to find an answer.
In turbo coding a $S$-random interleaver is a scrambling of the bits with the constraint that the distance of the previous $S$ indi...
Show that $$\frac{1}{n+1}+\frac{1}{n+2}+...+\frac{1}{3n+1}>1,\:\forall n\in\mathbb{N}$$
This is a 9th grade problem.
I was trying to take the greatest numerator, which is the last numerator of the last fraction. But there are only $2n+1$ terms. Right?
After that I have no idea. Thx!
