Question

8£®Ä³Ñ§Ð£ÉçÍÅÕÐƸ¹¤×÷ÈËÔ±£¬ÉèÖÃA¡¢BÁ½×é²âÊÔÏîÄ¿¹©Ó¦Æ¸ÈËԱѡÔñ£¬¼×¡¢ÒÒ¡¢±û¡¢¶¡ËÄÈ˲μÓӦƸ£¬ÆäÖмס¢ÒÒ¡¢±ûÈýÈ˸÷×Ô¶ÀÁ¢²Î¼ÓA×é²âÊÔ£¬ÒÑÖª¼×¡¢ÒÒÁ½È˸÷×Ôͨ¹ý²âÊԵĸÅÂʾùΪ$\frac{1}{2}$£¬±ûͨ¹ý²âÊԵĸÅÂÊΪ$\frac{3}{5}$£®¶¡²Î¼ÓB×é²âÊÔ£¬ÒÑÖªB×é¹²ÓÐ6µÀÊÔÌ⣬¶¡»á×öÆäÖеÄ4µÀÌ⣮¶¡Ö»ÄÜÇÒ±ØÐëÑ¡Ôñ4µÀÌâ×÷´ð£¬´ð¶Ô3µÀÌâÔò¾ºÆ¸³É¹¦£®
£¨¢ñ£©Çó¶¡Ó¦Æ¸³É¹¦µÄ¸ÅÂÊ£»
£¨¢ò£©¼Ç²âÊÔͨ¹ýµÄ×ÜÈËÊýΪ¦Î£¬Çó¦ÎµÄ·Ö²¼ÁкÍÆÚÍû£®

Answer 1

·ÖÎö £¨I£©ÉèʼþCΪ¶¡Ó¦Æ¸³É¹¦£¬ÔòÓÉÅÅÁÐ×éºÏ֪ʶ½áºÏµÈ¿ÉÄÜʼþ¸ÅÂʼÆË㹫ʽÄÜÇó³ö¶¡Ó¦Æ¸³É¹¦µÄ¸ÅÂÊ£®
£¨II£©ÓÉÌâÒâ¦ÎËùÓпÉÄܵÄֵΪ0£¬1£¬2£¬3£¬4£¬·Ö±ðÇó³öÏàÓ¦µÄ¸ÅÂÊ£¬ÓÉ´ËÄÜÇó³ö¦ÎµÄ·Ö²¼ÁкÍÆÚÍû£®

½â´ð £¨16£©£¨±¾Ð¡ÌâÂú·Ö13·Ö£©
£¨I£©ÉèʼþCΪ¶¡Ó¦Æ¸³É¹¦£¬ÔòP£¨C£©=$\frac{{C}_{4}^{3}{C}_{2}^{1}+{C}_{4}^{4}}{{C}_{6}^{4}}$=$\frac{3}{5}$£®¡­£¨4·Ö£©
£¨II£©ÓÉÌâÒâ¦ÎËùÓпÉÄܵÄֵΪ0£¬1£¬2£¬3£¬4£®¡­£¨5·Ö£©
P£¨¦Î=0£©=£¨1-$\frac{1}{2}$£©²¡Á£¨1-$\frac{3}{5}$£©²=$\frac{1}{25}$£¬
P£¨¦Î=1£©=${C}_{2}^{1}£¨\frac{1}{2}£©^{2}{C}_{2}^{0}£¨\frac{2}{5}£©^{2}{C}_{2}^{1}\frac{2}{5}¡Á\frac{3}{5}$=$\frac{1}{5}$£¬
P£¨¦Î=2£©=${C}_{2}^{2}£¨\frac{1}{2}£©^{2}{C}_{2}^{0}£¨\frac{2}{5}£©^{2}$+${C}_{2}^{1}£¨\frac{1}{2}£©^{2}{C}_{2}^{2}£¨\frac{3}{5}£©^{2}$=$\frac{37}{100}$£¬
P£¨¦Î=3£©=${C}_{2}^{2}£¨\frac{1}{2}£©^{2}{C}_{2}^{1}£¨\frac{1}{2}£©^{2}{C}_{2}^{2}£¨\frac{3}{5}£©^{2}$=$\frac{3}{10}$£¬
P£¨¦Î=4£©=${C}_{2}^{2}£¨\frac{1}{2}£©^{2}{C}_{2}^{2}£¨\frac{3}{5}£©^{2}$=$\frac{9}{100}$£¬
ËùÒԦεķֲ¼ÁÐΪ£º

¦Î	0	1	2	3	4
P	$\frac{1}{25}$	$\frac{1}{5}$	$\frac{37}{100}$	$\frac{3}{10}$	$\frac{9}{100}$

¡­£¨11·Ö£©
ËùÒÔËùÇóÊýѧÆÚÍûΪE¦Î=$0¡Á\frac{1}{25}+1¡Á\frac{1}{5}+2¡Á\frac{37}{100}$+3¡Á$\frac{3}{10}$+$4¡Á\frac{9}{100}$=$\frac{11}{5}$£®¡­£¨13·Ö£©

µãÆÀ ±¾Ì⿼²é¸ÅÂʵÄÇ󷨣¬¿¼²éÀëÉ¢ÐÍËæ»ú±äÁ¿µÄ·Ö²¼ÁкÍÊýѧÆÚÍûµÄÇ󷨣¬ÊÇÖеµÌ⣬½âÌâʱҪÈÏÕæÉóÌ⣬עÒâÅÅÁÐ×éºÏ֪ʶµÄºÏÀíÔËÓã®