Question

4．甲班人數(shù)比乙班人數(shù)少$\frac{1}{5}$，則乙班人數(shù)比甲班人數(shù)多（　�。�

• A． $\frac{1}{4}$
• B． $\frac{1}{5}$
• C． $\frac{4}{5}$

Answer 1

分析 甲班人數(shù)比乙班人數(shù)少$\frac{1}{5}$，把乙班人數(shù)看作單位“1”，則甲班人數(shù)相當于乙班人數(shù)的1-$\frac{1}{5}$=$\frac{4}{5}$，那么乙班人數(shù)比甲班人數(shù)多$\frac{1}{5}$÷$\frac{4}{5}$=$\frac{1}{4}$，計算即可．

解答 解：$\frac{1}{5}$÷（1-$\frac{1}{5}$）
=$\frac{1}{5}$÷$\frac{4}{5}$
=$\frac{1}{4}$
答：乙班人數(shù)比甲班人數(shù)多$\frac{1}{4}$．
故選：A．

點評 此題解答的關(guān)鍵是把乙班人數(shù)看作單位“1”，表示出甲班人數(shù)，進一步解決問題．