哪位G友能帮忙解答一下？

kingwin

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

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

这道题为何不选e??

For a convention, a hotel charges a daily room rate of $120 for 1 person and x dollars for each additional person.  What is the charge for each additional person?

(1)     The daily cost per person for 4 people sharing the cost of a room equally is $45.

(2)   The daily cost per person for 2 people sharing the cost of a room equally is $25 more than the corresponding cost for 4 people.

                  

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

谢谢G友的解疑！！！

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

这道题为何不选e??

For a convention, a hotel charges a daily room rate of $120 for 1 person and x dollars for each additional person.  What is the charge for each additional person?

(1)     The daily cost per person for 4 people sharing the cost of a room equally is $45.

(2)   The daily cost per person for 2 people sharing the cost of a room equally is $25 more than the corresponding cost for 4 people.

                  

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

谢谢G友的解疑！！！

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[此贴子已经被作者于2008-7-14 13:56:24编辑过]