果園里桃樹(shù)的棵數(shù)相當(dāng)于梨樹(shù)棵數(shù)的
,相當(dāng)于蘋果樹(shù)棵數(shù)的
.如果梨樹(shù)比蘋果樹(shù)少180棵,這個(gè)果園里有桃樹(shù)多少棵?
由于園里桃樹(shù)與梨樹(shù)的棵數(shù)的比為3:5,與蘋果樹(shù)的棵數(shù)比為3:7,
則梨樹(shù)的棵樹(shù)與蘋果樹(shù)的比為5:7;
180÷(1-
)×
=180×
×
,
=270(棵).
答:這個(gè)果園的桃樹(shù)有270棵.