题型:选择题 题类:其他 难易度:中档
测年份:2018
题型:选择题 题类:其他 难易度:中档
测年份:2018
我国古代数学著作\(《\)九章算术\(》\)中有如下问题“今有人持金出五关,前关二而税一,次关三而税一,次关四而税一,次关五而税一,次关六而税一,并五关所税,适重一斤。”其意思为“今有人持金出五关,第\(1\)关收税金为持金的\(\dfrac{1}{2}\),第\(2\)关收税金为剩余金的\(\dfrac{1}{3}\),第\(3\)关收税金为剩余金的\(\dfrac{1}{4}\),第\(4\)关收税金为剩余金的\(\dfrac{1}{5}\),第\(5\)关收税金为剩余金的\(\dfrac{1}{6}\)。\(5\)关所收税金之和,恰好重\(1\)斤”则在此问题中,第\(5\)关收税金
题型:选择题 题类:其他 难易度:中档
测年份:2018
已知数列\(\{a_{n}\}\):\( \dfrac{1}{2}\),\( \dfrac{1}{3}+ \dfrac{2}{3}\),\( \dfrac{1}{4}+ \dfrac{2}{4}+ \dfrac{3}{4}\),\( \dfrac{1}{5}+ \dfrac{2}{5}+ \dfrac{3}{5}+ \dfrac{4}{5}\),\(…\),那么数列\(\{b_{n}\}=\left\{ \left. \dfrac{1}{a_{n}a_{n+1}} \right. \right\}\)前\(n\)项的和为\((\) \()\)