求解几道数学题..

lebenkong

                   

 

 

 

 

Q7:

A certain university will select 1 of 7 candidates eligible to fill a position in the mathematics department and 2 of 10 candidates eligible to fill 2 identical positions in the computer science department.  If none of the candidates is eligible for a position in both departments, how many different sets of 3 candidates are there to fill the 3 positions?

 

 

 

 

A.     42

B.     70

C.     140

D.     165

E.      315

答案是E

Q13:

If n is a positive integer, what is the remainder when 3⁸ⁿ⁺³ + 2 is divided by 5?

 

 

 

 

A.     0

B.     1

C.     2

D.     3

E.      4

答案是E

 

Q14:

Of all the students in a certain dormitory,  are first-year students and the rest are second-year students.  If   of the first-year students have not declared a major and if the fraction of second-year students who have declared a major is 3 times the fraction of first-year students who have declared a major, what fraction of all the students in the dormitory are second-year students who have not declared a major?

 

 

 

 

A.1/15
              

B.1/5
           

C.4/15

D.1/3

E.2/5.     

答案是B

Q30:

The total cost of an office dinner was shared equally by k of the n employees who attended the dinner.  What was the total cost of the dinner?

(1)     Each of the k employees who shared the cost of the dinner paid $19.

(2)   If the total cost of the dinner had been shared equally by k + 1 of the n employees who attended the dinner, each of the k + 1 employees would have paid $18.

                  

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.

                                    答案是C

 

Q7:

A certain university will select 1 of 7 candidates eligible to fill a position in the mathematics department and 2 of 10 candidates eligible to fill 2 identical positions in the computer science department.  If none of the candidates is eligible for a position in both departments, how many different sets of 3 candidates are there to fill the 3 positions?

 

 

 

 

A.     42

B.     70

C.     140

D.     165

E.      315

答案是E

Q13:

If n is a positive integer, what is the remainder when 3⁸ⁿ⁺³ + 2 is divided by 5?

 

 

 

 

A.     0

B.     1

C.     2

D.     3

E.      4

答案是E

 

Q14:

Of all the students in a certain dormitory,  are first-year students and the rest are second-year students.  If   of the first-year students have not declared a major and if the fraction of second-year students who have declared a major is 3 times the fraction of first-year students who have declared a major, what fraction of all the students in the dormitory are second-year students who have not declared a major?

 

 

 

 

A.1/15
              

B.1/5
           

C.4/15

D.1/3

E.2/5.     

答案是B

Q30:

The total cost of an office dinner was shared equally by k of the n employees who attended the dinner.  What was the total cost of the dinner?

(1)     Each of the k employees who shared the cost of the dinner paid $19.

(2)   If the total cost of the dinner had been shared equally by k + 1 of the n employees who attended the dinner, each of the k + 1 employees would have paid $18.

                  

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.

                                    答案是C

 

[此贴子已经被作者于2007-12-23 0:46:54编辑过]

atc

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