问答题从序列{-2,-1,0,1,2}中任选两数,这两个数可以相等,求两个数和为零的概率?
问答题某项工程A、B两队合作完成需要12天,B、C两队合作需要15天完成,A、C两队合作需要20天完成,如果由A、B、C三队合作需要多少天完成?
问答题What are the factors of 60?
问答题What is the average of 2,4,8,0,1?
问答题某气象站天气预报准确率为80%,求5次预报中恰好有4次准确的概率?
问答题Bob年初往银行存款10000 ,年利率为12%,以复利两个月结算一次,问在年末他在银行存有多少钱?
问答题一列火车A早晨6点从甲地开往乙地,速度为45千米小时,另一列火车B在2个小时后从乙地开往甲地,速度比A快15千米小时,中午12时两车同时经过途中某站丙地,然后再继续前进,问B到达甲地时,A离乙地还有多远?
问答题有A、B、C、D、E 5个字母,从中取出1个,记下其值,然后再放回去,连续这样做,取出5个字母,排成一排,问恰好有4个字母相同的概率?
问答题一个口袋内装有3个小球,另一个口袋内装有5个小球,这些小球颜色各不相同。①如果从两个口袋内各取1个小球,有多少种不同的取法?②如果从两个口袋内任取1个小球,有多少种不同的取法?
问答题现在有1元人民币4张,2元人民币2张,10元人民币3张,从中至少取出1张,最多取出9张,共可以配成多少种钱数?
问答题12支铅笔分给甲、乙、丙3个人,每个人都必须是偶数支铅笔且每个人至少得到2支,一共有多少种分配方法?
问答题18,645,678是否能够被3整除?
问答题有3个打字员为4个科室服务,如果4个科室各有1份文件要录入,并且他们只能找这3个打字员录入,各科室对打字员的选择是随机的,问每个打字员都收到文件的概率是多少?
填空题A certain college has 8,978 full-time students
填空题.If the function g is defined for all nonzero numbers y by find the value of each of the following.
填空题40. There are a total of 20 dogs and cats at a kennel. If the ratio of the number of dogs to the number of cats at the kennel is 3 to 2, how many cats are at the kennel?
填空题39. Two cars started from the same point and traveled on a straight course in opposite directions for 2 hours, at which time they were 208 miles apart. If one car traveled, on average, 8 miles per hour faster than the other car, what was the average speed of each car for the 2-hour trip?
填空题.Solve each of the following inequalities for x.