数学题把我弄疯了，这几道拜托各位了！你们挽救的是我的生命！！

几道数学题弄的我好难受~~希望大家帮帮我~~谢谢喽！！

       1，If p, s, and t are positive prime numbers, what is the value of p³s³t³ ?

(1)     p³st = 728
            

(2)     t = 13                               答案A
                

2，A certain characteristic in a large population has a distribution that is symmetric about the mean m.  If 68 percent of the distribution lies within one standard deviation d of the mean, what percent of the distribution is less than m + d ?

               A.    16%
                        

               B.     32%

                      C.     48%

                      D.    84%

                      E.     92%              答案d 有翻译就更好了，嘿嘿

       3，,If x and y are integers, is y an even integer?

(1)     2y – x = x² – y²

(2)     x is an odd integer.                     答案A

4，Each of 20 parents chose one of five days from Monday through Friday to attend parent-teacher conferences.  If more parents chose Monday than Tuesday, did at least one of the parents choose Friday?

(1)     None of the five days was chosen by more than 5 parents.

(2)     More parents chose Monday than Wednesday.                  答案A

(1)     None of the five days was chosen by more than 5 parents.

(2)     More parents chose Monday than Wednesday.                  答案A

(1)     2y – x = x² – y²

(2)     x is an odd integer.                     答案A

4，Each of 20 parents chose one of five days from Monday through Friday to attend parent-teacher conferences.  If more parents chose Monday than Tuesday, did at least one of the parents choose Friday?

(1)     None of the five days was chosen by more than 5 parents.

(2)     More parents chose Monday than Wednesday.                  答案A

(1)     None of the five days was chosen by more than 5 parents.

(2)     More parents chose Monday than Wednesday.                  答案A

                      C.     48%

                      D.    84%

                      E.     92%              答案d 有翻译就更好了，嘿嘿

       3，,If x and y are integers, is y an even integer?

(1)     2y – x = x² – y²

(2)     x is an odd integer.                     答案A

4，Each of 20 parents chose one of five days from Monday through Friday to attend parent-teacher conferences.  If more parents chose Monday than Tuesday, did at least one of the parents choose Friday?

(1)     None of the five days was chosen by more than 5 parents.

(2)     More parents chose Monday than Wednesday.                  答案A

(1)     None of the five days was chosen by more than 5 parents.

(2)     More parents chose Monday than Wednesday.                  答案A

(1)     2y – x = x² – y²

(2)     x is an odd integer.                     答案A

4，Each of 20 parents chose one of five days from Monday through Friday to attend parent-teacher conferences.  If more parents chose Monday than Tuesday, did at least one of the parents choose Friday?

(1)     None of the five days was chosen by more than 5 parents.

(2)     More parents chose Monday than Wednesday.                  答案A

(1)     None of the five days was chosen by more than 5 parents.

(2)     More parents chose Monday than Wednesday.                  答案A

(2)     t = 13                               答案A
        

2，A certain characteristic in a large population has a distribution that is symmetric about the mean m.  If 68 percent of the distribution lies within one standard deviation d of the mean, what percent of the distribution is less than m + d ?

               A.    16%
                

               B.     32%

                      C.     48%

                      D.    84%

                      E.     92%              答案d 有翻译就更好了，嘿嘿

       3，,If x and y are integers, is y an even integer?

(1)     2y – x = x² – y²

(2)     x is an odd integer.                     答案A

4，Each of 20 parents chose one of five days from Monday through Friday to attend parent-teacher conferences.  If more parents chose Monday than Tuesday, did at least one of the parents choose Friday?

(1)     None of the five days was chosen by more than 5 parents.

(2)     More parents chose Monday than Wednesday.                  答案A

(1)     None of the five days was chosen by more than 5 parents.

(2)     More parents chose Monday than Wednesday.                  答案A

(1)     2y – x = x² – y²

(2)     x is an odd integer.                     答案A

4，Each of 20 parents chose one of five days from Monday through Friday to attend parent-teacher conferences.  If more parents chose Monday than Tuesday, did at least one of the parents choose Friday?

(1)     None of the five days was chosen by more than 5 parents.

(2)     More parents chose Monday than Wednesday.                  答案A

(1)     None of the five days was chosen by more than 5 parents.

(2)     More parents chose Monday than Wednesday.                  答案A

                      C.     48%

                      D.    84%

                      E.     92%              答案d 有翻译就更好了，嘿嘿

       3，,If x and y are integers, is y an even integer?

(1)     2y – x = x² – y²

(2)     x is an odd integer.                     答案A

4，Each of 20 parents chose one of five days from Monday through Friday to attend parent-teacher conferences.  If more parents chose Monday than Tuesday, did at least one of the parents choose Friday?

(1)     None of the five days was chosen by more than 5 parents.

(2)     More parents chose Monday than Wednesday.                  答案A

(1)     None of the five days was chosen by more than 5 parents.

(2)     More parents chose Monday than Wednesday.                  答案A

(1)     2y – x = x² – y²

(2)     x is an odd integer.                     答案A

4，Each of 20 parents chose one of five days from Monday through Friday to attend parent-teacher conferences.  If more parents chose Monday than Tuesday, did at least one of the parents choose Friday?

(1)     None of the five days was chosen by more than 5 parents.

(2)     More parents chose Monday than Wednesday.                  答案A

(1)     None of the five days was chosen by more than 5 parents.

(2)     More parents chose Monday than Wednesday.                  答案A

呵呵，谢啦，大家都LUCK ！！