Question

9£®ÒÑ֪ǣţ»¨µÄ»¨É«ÊÜÈý¶Ô¶ÀÁ¢ÒÅ´«µÄµÈλ»ùÒò£¨AºÍa¡¢BºÍb¡¢CºÍc£©¿ØÖÆ£¬Æä;ÈçͼËùʾ£¬ÆäÖÐÀ¶É«ºÍºìÉ«»ìºÏºóÏÔ×ÏÉ«£¬À¶É«ºÍ»ÆÉ«»ìºÏÐγÉÂÌÉ«£®ÏÖÓÐij×Ï»¨Ö²Öê×Ô½»×Ó´ú³öÏÖ°×»¨¡¢»Æ»¨£®¾Ý´ËÅжÏÏÂÁÐÐðÊö²»ÕýÈ·µÄÊÇ£¨¡¡¡¡£©

• A£® ×ÔÈ»ÖÖȺÖк컨ֲÖêµÄ»ùÒòÐÍÓÐ4ÖÖ
• B£® ÓÃÓÚ×Ô½»µÄ×Ï»¨Ö²ÖêµÄ»ùÒòÐÍΪAaBbCc
• C£® ×Ô½»×Ó´úÖÐÂÌ»¨Ö²ÎïºÍºì»¨Ö²ÖêµÄ±ÈÀý¿ÉÄܲ»Í¬
• D£® ×Ô½»×Ó´ú³öÏֵĻƻ¨Ö²ÖêµÄ±ÈÀýΪ$\frac{3}{64}$

Answer 1

·ÖÎö ¸ù¾ÝÌâÒâºÍͼʾ·ÖÎö¿ÉÖª£ºÍ¼Ê¾Îª¸÷ÖÖÉ«ËصĺϳÉ;¾¶£¬ÆäÖнöÓлùÒòC´æÔÚʱ£¬°×É«ÄÜת»¯ÎªÀ¶É«£»½öÓлùÒòA´æÔÚʱ£¬°×É«ÄÜת»¯Îª»ÆÉ«£»»ùÒòA¡¢B´æÔÚʱ£¬»ÆÉ«ÄÜת»¯ÎªºìÉ«£®ºìÉ«ÓëÀ¶É«»ìºÏ³ÊÏÖ×ÏÉ«£¬À¶É«Óë»ÆÉ«»ìºÏ³ÊÏÖÂÌÉ«£®Òò´Ë£¬×Ï»¨Ö²ÖêµÄ»ùÒòÐÍΪA_B_C_£¬À¶»¨Ö²ÖêµÄ»ùÒòÐÍΪaa__C_£¬»Æ»¨Ö²ÖêµÄ»ùÒòÐÍΪA_bbcc£¬ºì»¨Ö²ÖêµÄ»ùÒòÐÍΪA_B_cc£¬ÂÌ»¨Ö²ÖêµÄ»ùÒòÐÍΪA_bbC_£¬°×»¨Ö²ÖêµÄ»ùÒòÐÍΪaa__cc£®
ÏÖÓÐij×Ï»¨Ö²Öê×Ô½»×Ó´ú³öÏÖ°×»¨£¬ËùÒԿ϶¨º¬ÓÐa¡¢c»ùÒò£¬Òò´Ë£¬Ç×±¾×Ï»¨Ö²ÖêµÄ»ùÒòÐÍΪAaB_Cc£®µ±×Ï»¨Ö²ÖêµÄ»ùÒòÐÍΪAaBBCc£¬Ôòºó´ú²»»á³öÏֻƻ¨Ö²Ö꣬ËùÒÔÇ×±¾×Ï»¨Ö²ÖêµÄ»ùÒòÐÍΪAaBbCc£®

½â´ð ½â£ºA¡¢×ÔÈ»ÖÖȺÖк컨ֲÖêµÄ»ùÒòÐÍÓÐAABBcc¡¢AaBBcc¡¢AABbcc¡¢AaBbcc¹²4ÖÖ£¬AÕýÈ·£»
B¡¢¸ù¾Ý·ÖÎöÇ×±¾×Ï»¨Ö²ÖêµÄ»ùÒòÐÍΪAaBbCc£¬BÕýÈ·£»
C¡¢ÓÉÓÚÇ×±¾×Ï»¨Ö²ÖêµÄ»ùÒòÐÍΪAaBbCc£¬ËùÒÔµ±Ç×±¾×Ï»¨Ö²ÖêµÄ»ùÒòÐÍΪAaBbCcʱ£¬×Ô½»×Ó´úÖÐÂÌ»¨Ö²ÎA_bbC_£©µÄ¸ÅÂÊΪ$\frac{3}{4}$¡Á$\frac{1}{4}$¡Á$\frac{3}{4}$=$\frac{9}{64}$£¬ºì»¨Ö²Ö꣨A_B_cc£©µÄ¸ÅÂÊΪ$\frac{3}{4}$¡Á$\frac{3}{4}$¡Á$\frac{1}{4}$=$\frac{9}{64}$£¬ËùÒÔ±ÈÀýÏàͬͬ£¬C´íÎó£»
D¡¢Ç×±¾×Ï»¨Ö²ÖêµÄ»ùÒòÐÍΪAaBbCc£¬Ôò×Ô½»×Ó´ú³öÏֵĻƻ¨Ö²Ö꣨A_bbcc£©µÄ±ÈÀýΪ$\frac{3}{4}$¡Á$\frac{1}{4}$¡Á$\frac{1}{4}$=$\frac{3}{64}$£¬DÕýÈ·£®
¹ÊÑ¡£ºC£®

µãÆÀ ±¾Ìâ½áºÏ¸÷ÖÖÉ«ËصĺϳÉ;¾¶Í¼½â£¬¿¼²é»ùÒò×ÔÓÉ×éºÏ¶¨ÂɵÄʵÖʼ°Ó¦Óã¬ÒªÇó¿¼ÉúÕÆÎÕ»ùÒò×ÔÓÉ×Ժ϶¨ÂɵÄʵÖÊ£¬Äܸù¾ÝÌâ¸ÉºÍÌâͼÐÅÏ¢ÅжϻùÒòÐͼ°±íÏÖÐÍÖ®¼äµÄ¶ÔÓ¦¹Øϵ£¬ÔÙ¸ù¾ÝÌâÖоßÌåÒªÇó´ðÌ⣬עÒâÖð¶Ô·ÖÎö·¨µÄÓ¦Óã®