作业做对了a题,做错了b题,正确率是 A.a*b*100% B.b/a*100% C.a/(a+b)*100%

问题描述:

作业做对了a题,做错了b题,正确率是 A.a*b*100% B.b/a*100% C.a/(a+b)*100%
作业做对了a题,做错了b题,正确率是( ) A.a*b*100% B.b/a*100% C.a/(a+b)*100%

a/(a+b)*100%
选C啊.