last week a producing worker had gross earnings of $390.O if she worked more than 40 hours last week and was paid 1.5 times her regular hourly rate for each hour worked in excess of 40 hours ,how many hours did she work last week?

1,If she had worked 4 more hours last week, her gross earnings would have been $435.00
2, Her regular hourly rate last week was $7.5

第一个是不是不对啊，不能确定现在1定是超过40个小时，还是没超过40个小时，还可能38+4~~~

答案是D 我觉得应该是B，大家帮帮忙啊

（1）设没超过40小时的小时工资为X，则超过40小时的小时工资为1.5X

设上周的总工作时数为T，如果T<=36小时，则有

XT=390

XT+X*4=435

解得X=11.25,T=34.7符合条件

如果T>=40,

X*40+1.5X(T-40)=390

X*40+1.5X(T+4-40)=435

解得X=7.5，T=48符合条件

从上面即可看出（1）是不充分的。

支持选B。