一项工程 甲队单独完成需要20天,乙要30天,合作完成几分之几
一项工程 甲队单独完成需要20天,乙要30天,合作完成几分之几
........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................1/20+1/30=5/60=1/12
1/20+1/30=5/60=1/12