Question

15．果園里梨樹(shù)的棵數(shù)是蘋果樹(shù)的$\frac{2}{5}$．桃樹(shù)的棵數(shù)比蘋果樹(shù)多$\frac{1}{4}$．蘋果樹(shù)比桃樹(shù)少20棵．梨樹(shù)有多少棵？

Answer 1

分析 把蘋果樹(shù)的棵數(shù)看成單位“1”，桃樹(shù)的棵數(shù)比蘋果樹(shù)多$\frac{1}{4}$，它對(duì)應(yīng)的數(shù)量是20棵，由此根據(jù)分?jǐn)?shù)除法的意義求出蘋果樹(shù)的棵數(shù)，再用蘋果樹(shù)的棵數(shù)乘$\frac{2}{5}$就是梨樹(shù)的棵數(shù)．

解答 解：20÷$\frac{1}{4}$×$\frac{2}{5}$
=80×$\frac{2}{5}$
=32（棵）
答：梨樹(shù)有32棵．

點(diǎn)評(píng) 解答此類問(wèn)題，首先找清單位“1”，進(jìn)一步理清解答思路，列式的順序，從而較好的解答問(wèn)題．