1ï¼10个çä¸æ1个å红çï¼æ¯æ¬¡æ½1个ï¼æ½åä¸æ¾åï¼æ½10次ï¼é®ç¬¬K次ï¼Kå±äº[1ï¼10]ï¼æ½å°ç红ççæ¦çæ¯å¤å°ï¼ç¬¬I次æ½å°çº¢çä¸ç¬¬J次æ½å°çº¢ççäºä»¶æ¯å¦ç¬ç«
2ï¼å¦ä¸é¢ å¦ææ¾å åºè¯¥æä¹è§£ï¼
hikeççæ¡æ¯å¯¹çï¼ä½å´ç¯äºä¸ä¸ªæ¦å¿µä¸ç大é误ï¼æä¸å¾ä¸è¯´ä¸¤å¥ã
æ¾åå°æ½æ ·ï¼å次æ½æ ·çäºä»¶æ¯ç¸äºç¬ç«çï¼ä¸æ¾åå°æ½æ ·ï¼å次æ½æ ·çäºä»¶æ¯ä¸ç¸äºç¬ç«çã
å 为楼主好象ççæ³å¦ç¹ä¸è¥¿ï¼æ以说å¾è¯¦ç»äºã
ä¸æ¾åæ½æ ·ï¼ç¬¬k次æ½å°çº¢ççæ¦çæ¯1/10ï¼è¿æ¯ç¨å
¨æ¦çå
¬å¼æ±å¾çã说第k次æ½å°çº¢ççæ¦çæ¯1/10ï¼æ¯å¨ç¬¬ä¸æ¬¡è¿æ²¡ææ½åçæ¶å说çï¼å¦æ第ä¸æ¬¡æ½åå·²ç»å®æï¼åå¦æ第ä¸æ¬¡æ½å°çº¢çï¼ç¬¬k(k>1)次æ½å°çº¢ççæ¦ç为0ï¼å¦æ第ä¸æ¬¡æ½å°ç½çï¼ç¬¬k次æ½å°çº¢ççæ¦ç为1/9ï¼å¯è§å次æ½æ ·çæ¦çæ¯äºç¸å½±åçï¼ä¸æ¯ç¸äºç¬ç«çã
举ä¸ä¸ªç®åä¾åï¼å°±ç¨æ¬é®é¢ï¼ä½è¯´å¾æ´ç®åäºã
A1ï¼ç¬¬ä¸æ¬¡æ½å°çº¢çï¼B1ï¼ç¬¬ä¸æ¬¡æ½å°ç½ç
A2ï¼ç¬¬äºæ¬¡æ½å°çº¢çï¼B1ï¼ç¬¬äºæ¬¡æ½å°ç½ç
æ±ï¼ç¬¬ä¸æ¬¡æ½å°ç½çã第äºæ¬¡æ½å°çº¢ççæ¦çï¼å³æ±P(B1A2).
æ¾åå°æ½åï¼
P(B1A2)=P(B1)P(A2|B1)=P(B1)P(A2)=(9/10)(1/10)=9/100ã
è¿éB1ä¸A2ç¸äºç¬ç«ã
ä¸æ¾åå°æ½åï¼
P(B1A2)=P(B1)P(A2|B1)=ï¼9/10ï¼ï¼1/9ï¼=1/10ã
è¿éB1ä¸A2ä¸ç¸äºç¬ç«ï¼å³P(B1)P(A2|B1)â P(B1)P(A2ï¼ã
å 为è¯è®ºéä¸è½å¤ååï¼æåªè½å¨è¿éå说å å¥ã
B1A2称为B1ä¸A2ç积äºä»¶ï¼è¡¨ç¤ºB1ä¸A2åæ¶åçï¼æ±ç§¯äºä»¶çæ¦çç¨ä¹æ³å®ç
P(B1A2)=P(B1)P(A2|B1)ï¼è¿éP(A2|B1)表示B1åççæ¡ä»¶ä¸ï¼A2åççæ¦çï¼å³å¨ç¬¬ä¸æ¬¡æ½å°ç½ççæ¡ä»¶ä¸ï¼ç¬¬äºæ¬¡æ½å°çº¢ççæ¦çï¼å 为å¨æ¾åå°æ½åæ¡ä»¶ä¸ï¼ç¬¬äºæ¬¡æ½åæ¶ï¼å£è¢éä»ç¶æ10åªçï¼å
¶ä¸ä¸åªçº¢çï¼
æ
P(A2|B1)=1/10=P(A2);ä½å¨ä¸æ¾åå°æ½åæ¡ä»¶ä¸ï¼ç¬¬äºæ¬¡æ½åæ¶ï¼å£è¢éè¿æ9åªçï¼å
¶ä¸ä¸åªçº¢çï¼æ
P(A2|B1)=1/9ã
å¦æ积äºä»¶çæ¦ççäºä¸¤ä¸ªäºä»¶æ¦ççä¹ç§¯ï¼å³P(AB)=P(A)P(B),å称è¿ä¸¤ä¸ªäºä»¶æ¯ç¸äºç¬ç«çãä»ä¸é¢å¯ä»¥çåºï¼å¨æ¾åå°æ½åæ¶ï¼P(A2|B1)=P(A2);ä½å¨ä¸æ¾åå°æ½åæ¶ï¼P(A2|B1)=1/9â P(A2)=1/10ï¼è¿å°±æ¯è¯´ï¼å¨ä¸æ¾åå°æ½åæ¶ï¼äºä»¶æ¯ä¸ç¸äºç¬ç«çã
温馨提示:答案为网友推荐,仅供参考