need help, please!

If two regular six-sided dice are thrown, the probability that the sum will be a prime number is
a. 5/36 b. 1/6 c. 5/12 d. 1/2 e. 2/9



thank you very much!

所有跟帖： 

• 回复：5/12 -jinjing- ♀ (0 bytes) () 02/03/2010 postreply 11:15:40

• 5/36 -pj- ♂ (0 bytes) () 02/03/2010 postreply 13:04:32

• 回复：5/36 -jinjing- ♀ (19 bytes) () 02/04/2010 postreply 14:07:29

• 回复：回复：5/36 -guest007- ♀ (27 bytes) () 02/05/2010 postreply 10:58:48

• sorry -guest007- ♀ (26 bytes) () 02/05/2010 postreply 10:59:32

• 回复：回复：5/36 -pj- ♂ (91 bytes) () 02/06/2010 postreply 17:15:54

• 回复：回复：回复：5/36 -Jinjing- ♀ (78 bytes) () 02/07/2010 postreply 07:52:16

• You are right! -pj- ♂ (0 bytes) () 02/08/2010 postreply 14:08:47

• 回复：回复：回复：5/36 -wxczcbm- ♂ (160 bytes) () 02/07/2010 postreply 22:20:10

• 回复：回复：回复：回复：5/36 -greenfarm- ♀ (0 bytes) () 02/08/2010 postreply 10:13:27

• you are right. possibility for odd number is wrong -pj- ♂ (27 bytes) () 02/08/2010 postreply 14:09:53

• thank you very much! -greenfarm- ♀ (0 bytes) () 02/04/2010 postreply 09:11:23

• 回复：need help, please! -carrollton- ♂ (3 bytes) () 02/10/2010 postreply 17:42:33

• 回复：回复：need help, please! -Jinjing- ♀ (256 bytes) () 02/12/2010 postreply 12:48:16

• 为什么我算得是17/36？ -rsg11- ♂ (0 bytes) () 03/02/2010 postreply 16:30:40