标题: 数学菜鸟问几个题~~ [打印本页] 作者: 糊香肠 时间: 2010-7-15 12:06 标题: 数学菜鸟问几个题~~ 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
If n is the product of the integers from1 to 20 inclusive, what is the greatest integer k for which 2k is a factor of n?
A. 10 B. 12 C. 15 D. 18 E. 20
A gardener is going to plant 2 red rosebushes and 2 white rosebushes. If the gardener is to select each of the bushes at random, one at a time, and plant them in a row, what is the probability that the 2 rosebushes in the middle of the row will be the red rosebushes?
A. 1/12 B. 1/6 C. 1/5 D. 1/3 E. 1/2
A set of numbers has the property that for any number t in the set, t + 2 is in the set. If –1 is in the set, which of the following must also be in the set?
I. -3 II. 1 III. 5
A. I only B. II only C. I and II only D. II and III only E. I, II, and III
In a corporation, 50 percent of the male employees and 40 percent of the female employees are at least 35 years old. If 42 percent of all the employees are at least 35 years old, what fraction of the employees in the corporation are females?
A. 3/5 B. 2/3 C. 3/4 D. 4/5 E. 5/6
If n is an integer and 2 < n < 6, what is the value of n? (1) n is a factor of 15. (2) n is a factor of 21.
If 10的50次方 – 74 is written as an integer in base 10 notation, what is the sum of the digits in that integer?