{"id":25526,"date":"2021-12-24T17:10:17","date_gmt":"2021-12-24T10:10:17","guid":{"rendered":"https:\/\/www.vietlearn.org\/post\/?p=25526"},"modified":"2021-12-24T17:10:18","modified_gmt":"2021-12-24T10:10:18","slug":"bai-so-17-do-vui-luyen-tri-thong-minh","status":"publish","type":"post","link":"https:\/\/www.vietlearn.org\/kien-thuc\/bai-so-17-do-vui-luyen-tri-thong-minh\/","title":{"rendered":"B\u00c0I S\u1ed0 17 &#8211; \u0110\u1ed1 vui luy\u1ec7n tr\u00ed th\u00f4ng minh"},"content":{"rendered":"<h3><a id=\"post-25526-CAU_1_16\"><\/a>C\u00c2U 1:<\/h3>\n<p>H\u00ecnh n\u00e0o s\u1ebd b\u1ecb lo\u1ea1i trong nh\u1eefng h\u00ecnh d\u01b0\u1edbi \u0111\u00e2y:<\/p>\n<p><img fetchpriority=\"high\" decoding=\"async\" width=\"568\" height=\"127\" class=\"wp-image-25527\" src=\"https:\/\/www.vietlearn.org\/post\/wp-content\/uploads\/2021\/12\/33_1-jpg.jpeg\" alt=\"33_1.jpg\" srcset=\"https:\/\/www.vietlearn.org\/kien-thuc\/wp-content\/uploads\/2021\/12\/33_1-jpg.jpeg 568w, https:\/\/www.vietlearn.org\/kien-thuc\/wp-content\/uploads\/2021\/12\/33_1-jpg-300x67.jpeg 300w\" sizes=\"(max-width: 568px) 100vw, 568px\" \/><\/p>\n<h3><a id=\"post-25526-CAU_2_16\"><\/a>C\u00c2U 2:<\/h3>\n<p>H\u00ecnh n\u00e0o \u00edt gi\u1ed1ng nh\u1ea5t trong nh\u1eefng h\u00ecnh d\u01b0\u1edbi \u0111\u00e2y:<\/p>\n<p><img decoding=\"async\" width=\"568\" height=\"134\" class=\"wp-image-25528\" src=\"https:\/\/www.vietlearn.org\/post\/wp-content\/uploads\/2021\/12\/33_2-jpg.jpeg\" alt=\"33_2.jpg\" srcset=\"https:\/\/www.vietlearn.org\/kien-thuc\/wp-content\/uploads\/2021\/12\/33_2-jpg.jpeg 568w, https:\/\/www.vietlearn.org\/kien-thuc\/wp-content\/uploads\/2021\/12\/33_2-jpg-300x71.jpeg 300w\" sizes=\"(max-width: 568px) 100vw, 568px\" \/><\/p>\n<h3><a id=\"post-25526-CAU_3_16\"><\/a>C\u00c2U 3:<\/h3>\n<p>Trong m\u1ed9t th\u00e1ng n\u00e0o \u0111\u00f3 c\u00f3 3 ng\u00e0y ch\u1ee7 nh\u1eadt \u0111\u1ec1u l\u00e0 ng\u00e0y ch\u1eb5n (t\u1ee9c l\u00e0 ng\u00e0y mang s\u1ed1 ch\u1eb5n trong th\u00e1ng). H\u00e3y T\u00ednh xem ng\u00e0y 20 c\u1ee7a th\u00e1ng \u0111\u00f3 l\u00e0 ng\u00e0y th\u1ee9 m\u1ea5y trong tu\u1ea7n l\u1ec5?<\/p>\n<h3><a id=\"post-25526-CAU_4_14\"><\/a>C\u00c2U 4:<\/h3>\n<p>H\u00e3y \u0111i\u1ec1n 7 d\u1ea5u + v\u00e0 m\u1ed9t d\u1ea5u x \u0111\u1ec3 \u0111\u1eb3ng th\u1ee9c sau \u0111\u01b0\u1ee3c th\u00e0nh l\u1eadp (\u0111\u00fang, c\u00f3 ngh\u0129a)?<\/p>\n<p>1\u20262\u20263\u20264\u20265\u20266\u20267\u20268\u20269 = 100<\/p>\n<h3><a id=\"post-25526-CAU_5_8\"><\/a>C\u00c2U 5:<\/h3>\n<p>\u0110\u1ed1 vui b\u1ed5 \u00edch<\/p>\n<p>V\u1eeba h\u1ecdc v\u1eeba th\u00edch<\/p>\n<p>C\u00f9ng c\u01b0\u1eddi kh\u00fac kh\u00edch<\/p>\n<p>3 s\u1ed1 c\u00f3 T\u00edch<\/p>\n<p>\u0110\u00e2y b\u1eb1ng 60<\/p>\n<p>M\u1ed9t th\u1eeba s\u1ed1 l\u00e0 10<\/p>\n<p>\u0110\u1ed1 vui v\u1eeba h\u1ecdc v\u1eeba c\u01b0\u1eddi<\/p>\n<p>Hai th\u1eeba s\u1ed1 c\u00f2n l\u1ea1i, ai ng\u01b0\u1eddi t\u00ecm nhanh<\/p>\n<p>S\u1edbm khuya ch\u0103m ch\u1ec9 h\u1ecdc h\u00e0nh<\/p>\n<p>Sao \u0111\u1ea7u l\u1eafc l\u1eafc, sao \u0111\u00e0nh thua sao?<\/p>\n<h3><a id=\"post-25526-CAU_6_2\"><\/a>C\u00c2U 6:<\/h3>\n<p>\u0110\u1ed1 c\u00e1c b\u1ea1n v\u00e0o l\u00fac 3.661 gi\u00e2y qua n\u1eeda \u0111\u00eam ng\u00e0y \u0111\u1ea7u n\u0103m c\u1ee7a n\u0103m 2001 c\u00f3 g\u00ec l\u1ea1?<\/p>\n<h1>H\u01af\u1edaNG D\u1eaaN &#8211; B\u00c0I GI\u1ea2I &#8211; \u0110\u00c1P S\u1ed0<\/h1>\n<h2><a id=\"post-25526-BAI_SO_17_1\"><\/a>B\u00c0I S\u1ed0 17<\/h2>\n<h3><a id=\"post-25526-CAU_1_56\"><\/a>C\u00c2U 1:<\/h3>\n<p>H\u00ecnh b\u1ecb lo\u1ea1i l\u00e0 h\u00ecnh cu\u1ed1i c\u00f9ng. C\u00e1c h\u00ecnh kh\u00e1c l\u00e0 h\u00ecnh kh\u1ed1i trong h\u00ecnh h\u1ecdc. H\u00ecnh cu\u1ed1i c\u00f9ng l\u00e0 ch\u1eef.<\/p>\n<p><img decoding=\"async\" width=\"629\" height=\"194\" class=\"wp-image-25529\" src=\"https:\/\/www.vietlearn.org\/post\/wp-content\/uploads\/2021\/12\/132_1-jpg.jpeg\" alt=\"132_1.jpg\" srcset=\"https:\/\/www.vietlearn.org\/kien-thuc\/wp-content\/uploads\/2021\/12\/132_1-jpg.jpeg 629w, https:\/\/www.vietlearn.org\/kien-thuc\/wp-content\/uploads\/2021\/12\/132_1-jpg-300x93.jpeg 300w\" sizes=\"(max-width: 629px) 100vw, 629px\" \/><\/p>\n<h3><a id=\"post-25526-CAU_2_55\"><\/a>C\u00c2U 2:<\/h3>\n<p>H\u00ecnh b\u1ecb lo\u1ea1i l\u00e0 h\u00ecnh th\u1ee9 hai. C\u00e1c h\u00ecnh kh\u00e1c l\u00e0 h\u00ecnh \u0111a gi\u00e1c c\u00f3 c\u00e1c g\u00f3c, c\u00e1c c\u1ea1nh, ri\u00eang h\u00ecnh th\u1ee9 hai l\u00e0 h\u00ecnh tr\u00f2n n\u00f3 kh\u00f4ng c\u00f3 c\u00e1c g\u00f3c, c\u00e1c c\u1ea1nh.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"629\" height=\"188\" class=\"wp-image-25530\" src=\"https:\/\/www.vietlearn.org\/post\/wp-content\/uploads\/2021\/12\/132_2-jpg.jpeg\" alt=\"132_2.jpg\" srcset=\"https:\/\/www.vietlearn.org\/kien-thuc\/wp-content\/uploads\/2021\/12\/132_2-jpg.jpeg 629w, https:\/\/www.vietlearn.org\/kien-thuc\/wp-content\/uploads\/2021\/12\/132_2-jpg-300x90.jpeg 300w\" sizes=\"(max-width: 629px) 100vw, 629px\" \/><\/p>\n<h3><a id=\"post-25526-CAU_3_56\"><\/a>C\u00c2U 3:<\/h3>\n<p>B\u00e0i gi\u1ea3i:<\/p>\n<p>V\u00ec m\u1ed9t tu\u1ea7n c\u00f3 7 ng\u00e0y n\u00ean kh\u00f4ng th\u1ec3 c\u00f3 hai ng\u00e0y ch\u1ee7 nh\u1eadt v\u00e0 hai ng\u00e0y ch\u1eb5n li\u1ec1n nhau. V\u1eady gi\u1eefa hai ng\u00e0y ch\u1ee7 nh\u1eadt l\u00e0 ng\u00e0y ch\u1eb5n ph\u1ea3i c\u00f3 m\u1ed9t ng\u00e0y ch\u1ee7 nh\u1eadt l\u00e0 ng\u00e0y l\u1ebb.<\/p>\n<p>Trong th\u00e1ng \u0111\u00e3 c\u00f3 t\u1edbi 3 ng\u00e0y ch\u1ee7 nh\u1eadt l\u00e0 ng\u00e0y ch\u1eb5n v\u1eady th\u00e1ng \u1ea5y ph\u1ea3i c\u00f3 xen k\u1ebd hai ng\u00e0y ch\u1ee7 nh\u1eadt v\u00e0 ng\u00e0y l\u1ebb n\u1eefa. Suy ra trong th\u00e1ng n\u00e0y c\u00f3 5 ng\u00e0y ch\u1ee7 nh\u1eadt, v\u00e0 ng\u00e0y ch\u1ee7 nh\u1eadt \u0111\u1ea7u ti\u00ean l\u00e0 ng\u00e0y ch\u1eb5n.<\/p>\n<p>V\u00ec ng\u00e0y ch\u1ee7 nh\u1eadt th\u1ee9 nh\u1ea5t \u0111\u1ebfn ng\u00e0y ch\u1ee7 nh\u1eadt th\u1ee9 5 c\u00f3 t\u1edbi 7 x (5 \u2013 1) = 28 ng\u00e0y, m\u00e0 m\u1ed9t th\u00e1ng ch\u1ec9 c\u00f3 t\u1ed1i \u0111a l\u00e0 31 ng\u00e0y n\u00ean ng\u00e0y ch\u1ee7 nh\u1eadt th\u1ee9 nh\u1ea5t ch\u1ec9 c\u00f3 th\u1ec3 l\u00e0 m\u00f9ng m\u1ed9t, m\u00f9ng hai ho\u1eb7c m\u00f9ng 3.<\/p>\n<p>Song \u0111\u00f3 l\u1ea1i ph\u1ea3i l\u00e0 ng\u00e0y ch\u1eb5n n\u00ean ng\u00e0y ch\u1ee7 nh\u1eadt th\u1ee9 nh\u1ea5t l\u00e0 m\u00f9ng 2, suy ra ng\u00e0y m\u1ed3ng 9 v\u00e0 ng\u00e0y 16 c\u0169ng l\u00e0 ng\u00e0y ch\u1ee7 nh\u1eadt.<\/p>\n<p>Do \u0111\u00f3 ng\u00e0y 20 c\u1ee7a th\u00e1ng \u1ea5y l\u00e0 th\u1ee9 n\u0103m.<\/p>\n<h3><a id=\"post-25526-CAU_4_51\"><\/a>C\u00c2U 4:<\/h3>\n<p>\u0110\u00e1p s\u1ed1 : 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 x 9 = 100<\/p>\n<h3><a id=\"post-25526-CAU_5_35\"><\/a>C\u00c2U 5:<\/h3>\n<p>B\u00e0i gi\u1ea3i:<\/p>\n<p>Tr\u01b0\u1eddng h\u1ee3p 1:<\/p>\n<p>60 = 10 x ? x ?<\/p>\n<p>60 = 10 x 6 x 1<\/p>\n<p>V\u1eady 2 th\u1eeba s\u1ed1 c\u1ea7n t\u00ecm l\u00e0 6 v\u00e0 1<\/p>\n<p>Tr\u01b0\u1eddng h\u1ee3p 2:<\/p>\n<p>60 = 10 x ? x ?<\/p>\n<p>60= 10 x 2 x 3<\/p>\n<p>V\u1eady 2 th\u1eeba s\u1ed1 c\u1ea7n t\u00ecm l\u00e0 2 v\u00e0 3.<\/p>\n<p>\u0110\u00e1p s\u1ed1: 6 v\u00e0 1 ho\u1eb7c 2 v\u00e0 3.<\/p>\n<h3><a id=\"post-25526-CAU_6_16\"><\/a>C\u00c2U 6:<\/h3>\n<p>L\u00fac \u0111\u00f3 l\u00e0 1 gi\u1edd 1 ph\u00fat 1 gi\u00e2y c\u1ee7a ng\u00e0y m\u1edbi.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>C\u00c2U 1: H\u00ecnh n\u00e0o s\u1ebd b\u1ecb lo\u1ea1i trong nh\u1eefng h\u00ecnh d\u01b0\u1edbi \u0111\u00e2y: C\u00c2U 2: H\u00ecnh n\u00e0o \u00edt gi\u1ed1ng nh\u1ea5t trong nh\u1eefng h\u00ecnh d\u01b0\u1edbi \u0111\u00e2y: C\u00c2U 3: Trong m\u1ed9t th\u00e1ng n\u00e0o \u0111\u00f3 c\u00f3 3 ng\u00e0y ch\u1ee7 nh\u1eadt \u0111\u1ec1u l\u00e0 ng\u00e0y ch\u1eb5n (t\u1ee9c l\u00e0 ng\u00e0y mang s\u1ed1 ch\u1eb5n trong th\u00e1ng). H\u00e3y T\u00ednh xem ng\u00e0y 20 c\u1ee7a th\u00e1ng [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_disable_autopaging":false},"categories":[47],"tags":[],"class_list":["post-25526","post","type-post","status-publish","format-standard","hentry","category-do-vui"],"_links":{"self":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/25526","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/comments?post=25526"}],"version-history":[{"count":1,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/25526\/revisions"}],"predecessor-version":[{"id":25531,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/25526\/revisions\/25531"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=25526"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=25526"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=25526"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}