Question

13£®¶þ±¶Ìå¹ÛÉÍÖ²ÎïµÄ»¨É«£¨×ÏÉ«¡¢À¶É«¡¢°×É«£©ÓÉÈý¶Ô³£È¾É«ÌåÉϵĵÈλ»ùÒò£¨A¡¢a¡¢B¡¢b¡¢D¡¢d£©¿ØÖÆ£¬ÏÂͼΪ»ùÒò¿ØÖÆÎïÖʺϳɵÄ;¾¶£¬Çë·ÖÎöºó»Ø´ðÏÂÁÐÎÊÌ⣺

£¨1£©Ñо¿·¢ÏÖÖ²ÎﺬÓÐA¡¢B¡¢D»ùÒòʱ£¬Ö²ÎïÖ»ÄܺϳÉÓÐÉ«ÎïÖÊ I£¬²»ÄܺϳÉÓÐÉ«ÎïÖÊ¢ò£¬ÔòD»ùÒò¶ÔB»ùÒòµÄ±í´ïÓÐÒÖÖÆ ×÷Óã®
£¨2£©Ñ¡È¡´¿ºÏµÄ×Ï»¨ºÍ´¿ºÏµÄÀ¶»¨Ö²ÖêÔÓ½»£¬F₁ȫΪÀ¶»¨£¬F₂Öа׻¨£ºÀ¶»¨£º×Ï»¨=0£º91£º21£¬ÇëÍƲâÓÐÉ«ÎïÖÊ I´ú±íÀ¶É«£¨À¶É«»ò×ÏÉ«£©ÎïÖÊ£¬Ç×±¾ÖÐÀ¶»¨Ö²ÖêµÄ»ùÒòÐÍÊÇAAbbDD£®»ùÒòB¡¢bÓëD¡¢dÖ®¼äÊÇ£¨ÌîÊÇ¡¢·ñ£©×ñÑ­×ÔÓÉ×éºÏ¶¨ÂÉ£®
£¨3£©ÈôÈý¶Ô»ùÒò·Ö±ðλÓÚÈý¶Ô³£È¾É«ÌåÉÏ£¬½«»ùÒòÐÍΪaaBBDDµÄ¸öÌåÓë»ùÒòÐÍΪAAbbddµÄ¸öÌå½øÐÐÔÓ½»£¬F₁´ú×Ô½»£¬F₂Öа׻¨¡¢À¶»¨¡¢×Ï»¨Ö²ÖêµÄ±ÈÀýԼΪ16£º39£º9£®

Answer 1

·ÖÎö ·ÖÎöÌâÒ⣺ֲÎïµÄ»¨É«£¨×ÏÉ«¡¢À¶É«¡¢°×É«£©ÓÉÈý¶Ô³£È¾É«ÌåÉϵĵÈλ»ùÒò£¨A¡¢a¡¢B¡¢b¡¢D¡¢d£©¿ØÖÆ£¬Òò´ËÈý¶Ô»ùÒò×ñÑ­»ùÒòµÄ×ÔÓÉ×éºÏ¶¨ÂÉ£®
Ñ¡È¡´¿ºÏµÄ×Ï»¨ºÍ´¿ºÏµÄÀ¶»¨Ö²ÖêÔÓ½»£¬F₁ȫΪÀ¶»¨£¬F₂Öа׻¨£ºÀ¶»¨£º×Ï»¨=0£º91£º21£¬ÓÉÓÚÀ¶»¨ËùÕ¼±ÈÀý´ó£¬Òò´ËÍƲâÓÐÉ«ÎïÖÊ I´ú±íÀ¶É«ÎïÖÊ£¬ÔòÓÐÉ«ÎïÖÊ¢ò±íʾ×ÏÉ«ÎïÖÊ£¬Ôò°×»¨»ùÒòÐÍ¿ÉÒÔ±íʾΪaa____£¬À¶»¨»ùÒòÐÍ¿ÉÒÔ±íʾΪA___D_¡¢A_bbdd£¬×Ï»¨»ùÒòÐÍ¿ÉÒÔ±íʾΪA_B_dd£®

½â´ð ½â£º£¨1£©Ñо¿·¢ÏÖÖ²ÎﺬÓÐA¡¢B¡¢D»ùÒòʱ£¬Ö²ÎïÖ»ÄܺϳÉÓÐÉ«ÎïÖÊ I£¬²»ÄܺϳÉÓÐÉ«ÎïÖÊ¢ò£¬±íÃ÷D»ùÒò¶ÔB»ùÒòµÄ±í´ïÓÐÒÖÖÆ×÷Óã®
£¨2£©ÓÉ·ÖÎö¿ÉÖª£¬ÓÐÉ«ÎïÖÊ I´ú±íÀ¶É«ÎïÖÊ£¬ÔòÓÐÉ«ÎïÖÊ¢ò±íʾ×ÏÉ«ÎïÖÊ£¬²¢ÇÒÇ×±¾ÖÐ×Ï»¨Ö²Öê»ùÒòÐÍΪAABBdd£»´¿ºÏÀ¶»¨Ö²Öê»ùÒòÐÍÓÐAABBDD¡¢AAbbDD¡¢AAbbdd£¬ÆäÖÐAAbbddÓëAABBddÔÓ½»ºó´úȫΪ×ÏÉ«£¬²»·ûºÏÒªÇó£¬Ö»ÓÐAAbbDDÓëAABBddÔÓ½»µÄ×Ó¶þ´úÖÐ×Ï»¨Ö²Öê±ÈÀýΪ$\frac{21}{91+21}=\frac{3}{16}$£¬Òò´ËÇ×±¾ÖÐÀ¶»¨Ö²ÖêµÄ»ùÒòÐÍÊÇAAbbDD£®ÓÉÓÚ»ùÒò¾ùλÓÚ·ÇͬԴȾɫÌåÉÏ£¬Òò´Ë»ùÒòB¡¢bÓëD¡¢dÖ®¼ä×ñÑ­×ÔÓÉ×éºÏ¶¨ÂÉ£®
£¨3£©ÈôÈý¶Ô»ùÒò·Ö±ðλÓÚÈý¶Ô³£È¾É«ÌåÉÏ£¬½«»ùÒòÐÍΪaaBBDDµÄ¸öÌåÓë»ùÒòÐÍΪAAbbddµÄ¸öÌå½øÐÐÔÓ½»£¬F₁´ú£¨AaBbDd£©×Ô½»£¬F₂Öа׻¨Ö²Ö꣨aa____£©µÄ±ÈÀý=$\frac{1}{4}¡Á1¡Á1=\frac{1}{4}$¡¢×Ï»¨Ö²Ö꣨A_B_dd£©µÄ±ÈÀý=$\frac{3}{4}¡Á\frac{3}{4}¡Á\frac{1}{4}=\frac{9}{64}$£¬ÔòÀ¶»¨Ö²Öê±ÈÀýΪ$\frac{39}{64}$£®
¹Ê´ð°¸Îª£º
£¨1£©ÒÖÖÆ   
£¨2£©À¶É«     AAbbDD    ÊÇ  
£¨3£©16£º39£º9

µãÆÀ ±¾Ì⿼²éÁË»ùÒòÓëÐÔ×´µÄ¹ØϵÒÔ¼°»ùÒòµÄ×ÔÓÉ×éºÏ¶¨ÂÉ£¬ÒªÇó¿¼ÉúÄܹ»¸ù¾ÝÌâ¸ÉÐÅϢȷ¶¨ÓÐÉ«ÎïÖʵÄÖÖÀ࣬Ȼºó¸ù¾Ýͼ½âÈ·¶¨¸÷±íÏÖÐͶÔÓ¦µÄ»ùÒòÐÍ£¬ÔÙÀûÓûùÒòµÄ×ÔÓÉ×éºÏ¶¨ÂɽøÐÐÏà¹Ø¸ÅÂʵļÆË㣬¾ßÓÐÒ»¶¨µÄÄѶȣ®