张师傅和李师傅加工零件,张师傅加工500个,合格率90%.李师傅加工合格285合格率95%.
问题描述:
张师傅和李师傅加工零件,张师傅加工500个,合格率90%.李师傅加工合格285合格率95%.
问;这批零件合格率是多少
答
(500×90%+285)÷(500+285÷95%)
=735÷800
=91.875%