解:设全书有X页,X-(1/3X)+(1/4X)=60
X-7/12X=60
5/12X=60
X=144
答:这本书一共有144页
60÷(1-3分之1-4分之1)
=60÷(1-12分之7)
=60÷12分之5
=60×5分之12
=144(页)
60÷(1-1/3-1/4)
=60÷(12/12-4/12-3/12)
=60÷5/12
=60×12/5
=144
60÷(1-1/3-1/4)=144