修一条水渠,第一天修了全场的50%,第二天修了全场的30%,还剩160米没修.这条水渠全长多少米?

问题描述:

修一条水渠,第一天修了全场的50%,第二天修了全场的30%,还剩160米没修.这条水渠全长多少米?