A= 1/2 . 3/4 . 5/6 … 1599/1600 cmr A <2/3. 4/5 . 6/7... 1600/1601 help meee nhanh các cậu ơi

Ta có

$\dfrac{1}{2} < \dfrac{2}{3}, \dfrac{3}{4} < \dfrac{4}{5}, \dots, \dfrac{1599}{1600} < \dfrac{1600}{1601}$

Do đó ta có

$A = \dfrac{1}{2} . \dfrac{3}{4} . \dots . \dfrac{1599}{1600} < \dfrac{2}{3} . \dfrac{4}{5} . \dots . \dfrac{1600}{1601}$