修一水渠,前12天每天修13.2m,后18天每天修15.4m,一共修了多少米
问题描述:
修一水渠,前12天每天修13.2m,后18天每天修15.4m,一共修了多少米
答
13.2×12+15.4×18
=158.4+277.2
=435.6(米)
答:一共修了435.6米