标题: 请教数学题 [打印本页] 作者: 11502 时间: 2010-8-7 15:40 标题: 请教数学题 1.A certain roller coaster has 3 cars, and a passenger is equally likely to ride in any 1 of the 3 cars each time that passenger rides the roller coaster. If a certain passenger is to ride the roller coaster 3 times, what is the probability that the passenger will ride in each of the 3 cars?
A. 0 B. 1/9 C. 2/9 D. 1/3 E. 1 2.If 1050 – 74 is written as an integer in base 10 notation, what is the sum of the digits in that integer?
A. 424 B. 433 C. 440 D. 449 E. 467作者: 11502 时间: 2010-8-7 16:11 作者: fly12404 时间: 2010-8-7 16:20
1) 分母: 3種選擇 玩三次 = 3^3 =27 分子: 三種車都玩到 順序隨便 = 3! =6 6/ 27 = 2/9
