I think we should change 16 to 20....we get C(24,4)=...
how to understand: must be invested among 4 possible opportuniti
even if we should change 16 to 20....we get C(21,4)=...
sorry, C(21,4)=... wrong; C(24,4)=... right,if we should change
jinjing
2010-09-08 09:35:30I think we should change 16 to 20....we get C(24,4)=...