Question Number 32291 by abdo imad last updated on 22/Mar/18
$${let}\:{u}_{{n}} =\:\sum_{{k}=\mathrm{1}} ^{{n}} \:\frac{\mathrm{1}}{{n}+{k}}\:{prove}\:{that}\:\mathrm{0}\leqslant{u}_{{n}} \leqslant\mathrm{1}\:. \\ $$
let-u-n-k-1-n-1-n-k-prove-that-0-u-n-1-