单选题 You are working on a software development project and there is 60% probability that development will be completed by the planned date and 70% probability that testing will be completed by the planned date．What is the probability that development and testing will be completed as per schedule?

A、 65%．
B、 42%．
C、 66%．
D、 63%．

【正确答案】 B

【答案解析】[解析] 你工作在一个软件开发项目上，开发工作有60%的概率按计划日期完成；测试工作有70%的概率按计划日期完成。开发和测试工作都按照计划日期完成的概率是多少? A) 65%。 B) 42%。 C) 66%。 D) 63%。开发和测试同时按计划完成的概率是：60%×70%=42%。