The operation* represents either addition, subtraction, or multiplication of integers, what is the value of 1*0? (1) 0*2=2 (2) 2*0=2 我觉得这题应该选D,因为第二个式子不管是加还是减都可以得出2,所以1+0和-0的答案是唯一确定的。但是答案是A。请问到底选什么啊?答案唯一难道就不能选么?
A shipment of 8 television sets contains 2 black-and-white sets and 6color sets. If 2 television sets are to be chosen at random from this shipment, what is the probability that at least 1 of the 2 sets chosen will be a black-and-white set? A. 1/7 B. ¼ C. 5/14 D. 11/28 E. 13/26 答案是E。我怎么不会做了,我觉得应该是13/28啊 谢谢了啊
谢谢大家啊,那再问一题 From May 1 to May 30 in the same year, the balance in a checking account increased. What was the balance in the checking account on May 30?
(1)If, during this period of time, the increase in the balance in the checking account had been 12 percent, then the balance in the account on May 30 would have been $504
(2)During this period of time, the increase in the balance in the checking account was 8 percent. 这题我选的是C,答案是A。答案错了吧?