设梨树有X棵,则桃树有3/5X棵,苹果树有3/5X÷2/7=7/5X棵7/5X-X=222/5X=22X=55棵55x3/5=33棵55x7/5=77棵∴桃树有33棵,梨树有55棵,苹果数有77棵
桃:梨=3/5=6/10