{"id":25543,"date":"2021-12-24T17:15:28","date_gmt":"2021-12-24T10:15:28","guid":{"rendered":"https:\/\/www.vietlearn.org\/post\/?p=25543"},"modified":"2021-12-24T17:15:28","modified_gmt":"2021-12-24T10:15:28","slug":"bai-so-21-do-vui-luyen-tri-thong-minh","status":"publish","type":"post","link":"https:\/\/www.vietlearn.org\/kien-thuc\/bai-so-21-do-vui-luyen-tri-thong-minh\/","title":{"rendered":"B\u00c0I S\u1ed0 21 – \u0110\u1ed1 vui luy\u1ec7n tr\u00ed th\u00f4ng minh"},"content":{"rendered":"

<\/a>C\u00c2U 1:<\/h3>\n

N\u0103m b\u1ea1n \u0111o\u00e1n tu\u1ed5i v\u00e0 ng\u00e0y, th\u00e1ng sinh nh\u1eadt c\u1ee7a c\u00f4 gi\u00e1o.<\/p>\n\n\n\n\n\n\n\n\n
B\u1ea1n<\/td>\nTu\u1ed5i<\/td>\nNg\u00e0y<\/td>\nTh\u00e1ng<\/td>\n<\/tr>\n
T\u00edn<\/td>\n25<\/td>\n10<\/td>\n3<\/td>\n<\/tr>\n
D\u0169ng<\/td>\n27<\/td>\n11<\/td>\n4<\/td>\n<\/tr>\n
Minh<\/td>\n25<\/td>\n11<\/td>\n4<\/td>\n<\/tr>\n
Trang<\/td>\n25<\/td>\n11<\/td>\n3<\/td>\n<\/tr>\n
H\u01b0\u01a1ng<\/td>\n27<\/td>\n10<\/td>\n3<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Bi\u1ebft r\u1eb1ng c\u00f3 1 b\u1ea1n \u0111o\u00e1n \u0111\u00fang ho\u00e0n to\u00e0n, c\u00f2n 4 b\u1ea1n kh\u00e1c kh\u00f4ng \u0111o\u00e1n sai ho\u00e0n to\u00e0n. B\u1ea1n c\u00f3 \u0111o\u00e1n \u0111\u01b0\u1ee3c kh\u00f4ng?<\/p>\n

<\/a>C\u00c2U 2:<\/h3>\n

T\u00ecm tr\u00e1i b\u00f3ng c\u00f3 tr\u1ecdng l\u01b0\u1ee3ng kh\u00e1c nhau (10 tr\u00e1i).<\/p>\n

C\u00f3 m\u01b0\u1eddi (10) tr\u00e1i b\u00f3ng gi\u1ed1ng nhau (h\u00ecnh d\u00e1ng b\u00ean ngo\u00e0i) trong \u0111\u00f3 c\u00f3 ch\u00edn (9) tr\u00e1i c\u00f3 tr\u1ecdng l\u01b0\u1ee3ng b\u1eb1ng nhau v\u00e0 m\u1ed9t (1) tr\u00e1i c\u00f3 tr\u1ecdng l\u01b0\u1ee3ng kh\u00e1c (c\u00f3 th\u1ec3 nh\u1eb9 h\u01a1n ho\u1eb7c n\u1eb7ng h\u01a1n). D\u00f9ng m\u1ed9t c\u00e2n b\u00e0n v\u00e0 cho ph\u00e9p c\u00e2n ba (3) l\u1ea7n, b\u1ea1n h\u00e3y ch\u1ec9 ra tr\u00e1i b\u00f3ng c\u00f3 tr\u1ecdng l\u01b0\u1ee3ng kh\u00e1c \u0111\u00f3.<\/p>\n

<\/a>C\u00c2U 3:<\/h3>\n

Ba l\u1edbp g\u00f3p b\u00e1nh \u0111\u1ec3 li\u00ean hoan cu\u1ed1i n\u0103m. L\u1edbp A g\u00f3p 5kg b\u00e1nh, l\u1edbp B \u0111em \u0111\u1ebfn 3kg b\u00e1nh c\u00f9ng lo\u1ea1i. S\u1ed1 b\u00e1nh \u0111\u00f3 \u0111\u1ee7 d\u00f9ng cho 3 l\u1edbp n\u00ean l\u1edbp C kh\u00f4ng ph\u1ea3i mua b\u00e1nh m\u00e0 ph\u1ea3i tr\u1ea3 l\u1ea1i hai l\u1edbp kia 24 \u0111\u1ed3ng. H\u1ecfi m\u1ed7i l\u1edbp A, B nh\u1eadn bao nhi\u00eau ti\u1ec1n? (Ba l\u1edbp g\u00f3p b\u1eb1ng nhau).<\/p>\n

<\/a>C\u00c2U 4:<\/h3>\n

C\u00f3 4 h\u1ecdc sinh<\/a>: H\u00e0, Tu\u1ea5n, Minh v\u00e0 Th\u1eafng \u0111ang ng\u1ed3i trong 1 c\u0103n ph\u00f2ng:<\/p>\n

    \n
  1. H\u00e0 kh\u00f4ng s\u1eeda \u00e1o v\u00e0 kh\u00f4ng \u0111\u1ecdc s\u00e1ch.<\/li>\n
  2. Tu\u1ea5n kh\u00f4ng vi\u1ebft th\u01b0 v\u00e0 kh\u00f4ng s\u1eeda \u00e1o.<\/li>\n
  3. N\u1ebfu h\u00e0 kh\u00f4ng vi\u1ebft th\u01b0 th\u00ec minh kh\u00f4ng s\u1eeda \u00e1o.<\/li>\n
  4. Th\u1eafng kh\u00f4ng \u0111\u1ecdc s\u00e1ch v\u00e0 kh\u00f4ng s\u1eeda \u00e1o.<\/li>\n
  5. Minh kh\u00f4ng \u0111\u1ecdc s\u00e1ch v\u00e0 kh\u00f4ng vi\u1ebft th\u01b0.<\/li>\n<\/ol>\n

    B\u1ea1n n\u00f3i ch\u00ednh x\u00e1c xem 4 b\u1ea1n \u0111ang l\u00e0m g\u00ec?<\/p>\n

    H\u01af\u1edaNG D\u1eaaN – B\u00c0I GI\u1ea2I – \u0110\u00c1P S\u1ed0<\/h1>\n

    <\/a>B\u00c0I S\u1ed0 21<\/h2>\n

    <\/a>C\u00c2U 1:<\/h3>\n\n\n\n\n\n\n\n\n
    B\u1ea1n<\/td>\nTu\u1ed5i<\/td>\nNg\u00e0y<\/td>\nTh\u00e1ng<\/td>\n<\/tr>\n
    T\u00edn<\/td>\n25<\/td>\n10<\/td>\n3<\/td>\n<\/tr>\n
    D\u0169ng<\/td>\n27<\/td>\n11<\/td>\n4<\/td>\n<\/tr>\n
    Minh<\/td>\n25<\/td>\n11<\/td>\n4<\/td>\n<\/tr>\n
    Trang<\/td>\n25<\/td>\n11<\/td>\n3<\/td>\n<\/tr>\n
    H\u01b0\u01a1ng<\/td>\n27<\/td>\n10<\/td>\n3<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    Nh\u00ecn v\u00e0o b\u1ea3ng ta th\u1ea5y: b\u1ea1n T\u00edn v\u00e0 b\u1ea1n D\u0169ng \u0111o\u00e1n kh\u00e1c nhau ho\u00e0n to\u00e0n n\u00ean n\u1ebfu b\u1ea1n n\u00e0y \u0111o\u00e1n \u0111\u00fang ho\u00e0n to\u00e0n th\u00ec b\u1ea1n kia \u0111o\u00e1n sai ho\u00e0n to\u00e0n (lo\u1ea1i). T\u01b0\u01a1ng t\u1ef1 v\u00ec b\u1ea1n Minh v\u00e0 b\u1ea1n H\u01b0\u01a1ng \u0111o\u00e1n kh\u00e1c nhau ho\u00e0n to\u00e0n n\u00ean n\u1ebfu b\u1ea1n n\u00e0y \u0111o\u00e1n \u0111\u00fang ho\u00e0n to\u00e0n th\u00ec b\u1ea1n kia \u0111o\u00e1n sai ho\u00e0n to\u00e0n (lo\u1ea1i). Do \u0111\u00f3 c\u1ea3 4 b\u1ea1n T\u00edn, D\u0169ng, Minh, H\u01b0\u01a1ng \u0111\u1ec1u kh\u00f4ng \u0111o\u00e1n \u0111\u00fang ho\u00e0n to\u00e0n. Nh\u01b0 v\u1eady ch\u1ec9 c\u00f2n m\u1ed7i b\u1ea1n trang \u0111o\u00e1n \u0111\u00fang ho\u00e0n to\u00e0n. Khi \u0111\u00f3 b\u1ea1n T\u00edn \u0111o\u00e1n \u0111\u00fang tu\u1ed5i v\u00e0 th\u00e1ng, b\u1ea1n D\u0169ng \u0111o\u00e1n \u0111\u00fang ng\u00e0y, b\u1ea1n Minh \u0111o\u00e1n \u0111\u00fang tu\u1ed5i v\u00e0 ng\u00e0y, b\u1ea1n H\u01b0\u01a1ng \u0111o\u00e1n \u0111\u00fang th\u00e1ng. \u0110i\u1ec1u n\u00e0y ph\u00f9 h\u1ee3p v\u1edbi \u0111i\u1ec1u ki\u1ec7n c\u1ee7a \u0111\u1ec1 b\u00e0i l\u00e0 1 b\u1ea1n \u0111o\u00e1n \u0111\u00fang ho\u00e0n to\u00e0n (b\u1ea1n Trang) v\u00e0 4 b\u1ea1n c\u00f2n l\u1ea1i kh\u00f4ng \u0111o\u00e1n sai ho\u00e0n to\u00e0n.<\/p>\n

    V\u1eady b\u1ea1n Trang \u0111\u00e3 \u0111o\u00e1n \u0111\u00fang. C\u00f4 gi\u00e1o sinh ng\u00e0y 11 th\u00e1ng 3 v\u00e0 c\u00f4 25 tu\u1ed5i.<\/p>\n

    <\/a>C\u00c2U 2:<\/h3>\n

    B\u00e0i gi\u1ea3i:<\/p>\n

    G\u1ecdi tr\u00e1i b\u00f3ng kh\u00e1c bi\u1ec7t l\u00e0 tr\u00e1i gi\u1ea3.<\/p>\n

    Chia 10 tr\u00e1i b\u00f3ng l\u00e0m 3 nh\u00f3m A, B v\u00e0 C, g\u1ed3m 3, 3 v\u00e0 4 tr\u00e1i.<\/p>\n

    – C\u00e2n hai nh\u00f3m A v\u00e0 B l\u1ea7n 1.<\/p>\n

    * Tr\u01b0\u1eddng h\u1ee3p 1:<\/p>\n

    – C\u00e2n l\u1ea7n 1 b\u1eb1ng nhau: nh\u00f3m A v\u00e0 B l\u00e0 th\u1eadt, tr\u00e1i gi\u1ea3 trong nh\u00f3m C.<\/p>\n

    L\u1ea5y 2 tr\u00e1i nh\u00f3m C c\u00e2n v\u1edbi 2 tr\u00e1i c\u1ee7a nh\u00f3m A: c\u00e2n l\u1ea7n 2.<\/p>\n

    + N\u1ebfu c\u00e2n l\u1ea7n 2 b\u1eb1ng nhau th\u00ec tr\u00e1i gi\u1ea3 trong 2 tr\u00e1i c\u00f2n l\u1ea1i c\u1ee7a nh\u00f3m C.<\/p>\n

    – C\u00e2n 1 tr\u00e1i nh\u00f3m A v\u1edbi 1 trong hai tr\u00e1i c\u00f2n l\u1ea1i \u0111\u00f3: c\u00e2n l\u1ea7n 3.<\/p>\n

    N\u1ebfu kh\u00f4ng b\u1eb1ng nhau th\u00ec tr\u00e1i gi\u1ea3 l\u00e0 tr\u00e1i tr\u00ean b\u00e0n c\u00e2n, n\u1ebfu b\u1eb1ng nhau th\u00ec tr\u00e1i gi\u1ea3 l\u00e0 tr\u00e1i c\u00f2n l\u1ea1i.<\/p>\n

    + N\u1ebfu c\u00e2n l\u1ea7n 2 kh\u00f4ng b\u1eb1ng nhau th\u00ec tr\u00e1i gi\u1ea3 l\u00e0 2 tr\u00e1i nh\u00f3m C v\u00e0 bi\u1ebft l\u00e0 nh\u1eb9 hay n\u1eb7ng.<\/p>\n

    – C\u00e2n 1 tr\u00e1i nh\u00f3m A v\u1edbi 1 trong hai tr\u00e1i \u0111\u00f3: c\u00e2n l\u1ea7n 3.<\/p>\n

    N\u1ebfu kh\u00f4ng b\u1eb1ng nhau th\u00ec tr\u00e1i gi\u1ea3 l\u00e0 tr\u00e1i tr\u00ean b\u00e0n c\u00e2n, n\u1ebfu b\u1eb1ng nhau th\u00ec tr\u00e1i gi\u1ea3 l\u00e0 tr\u00e1i c\u00f2n l\u1ea1i.<\/p>\n

    * Tr\u01b0\u1eddng h\u1ee3p 2:<\/p>\n

    C\u00e2n l\u1ea7n 1 kh\u00f4ng b\u1eb1ng nhau: nh\u00f3m C l\u00e0 th\u1eadt.<\/p>\n

    Gi\u1ea3 d\u1ee5 nh\u00f3m A nh\u1eb9 h\u01a1n. C\u00e2n nh\u00f3m A v\u1edbi 3 tr\u00e1i nh\u00f3m C: c\u00e2n l\u1ea7n 2.<\/p>\n

    + N\u1ebfu c\u00e2n l\u1ea7n 2 b\u1eb1ng nhau th\u00ec nh\u00f3m B c\u00f3 tr\u00e1i gi\u1ea3 v\u00e0 tr\u00e1i gi\u1ea3 n\u1eb7ng h\u01a1n.<\/p>\n

    C\u00e2n hai tr\u00e1i nh\u00f3m B: c\u00e2n l\u1ea7n 3.<\/p>\n

    + N\u1ebfu c\u00e2n th\u0103ng b\u1eb1ng th\u00ec: tr\u00e1i gi\u1ea3 l\u00e0 tr\u00e1i th\u1ee9 3 c\u1ee7a nh\u00f3m B, n\u1ebfu kh\u00f4ng c\u00e2n b\u1eb1ng th\u00ec tr\u00e1i b\u00ean n\u1eb7ng l\u00e0 tr\u00e1i gi\u1ea3.<\/p>\n

    + N\u1ebfu c\u00e2n l\u1ea7n 2 kh\u00f4ng b\u1eb1ng nhau th\u00ec nh\u00f3m a c\u00f3 tr\u00e1i gi\u1ea3 v\u00e0 tr\u00e1i gi\u1ea3 nh\u1eb9 h\u01a1n.<\/p>\n

    C\u00e2n hai tr\u00e1i nh\u00f3m A: c\u00e2n l\u1ea7n 3.<\/p>\n

    + N\u1ebfu c\u00e2n th\u0103ng b\u1eb1ng th\u00ec tr\u00e1i gi\u1ea3 l\u00e0 tr\u00e1i th\u1ee9 3 c\u1ee7a nh\u00f3m A, n\u1ebfu kh\u00f4ng cho c\u00e2n b\u1eb1ng th\u00ec tr\u00e1i b\u00ean nh\u1eb9 l\u00e0 tr\u00e1i gi\u1ea3.<\/p>\n

    + N\u1ebfu d\u00f9ng nh\u00f3m B (nh\u00f3m n\u1eb7ng) thay cho nh\u00f3m A. C\u00e2n nh\u00f3m B v\u1edbi 3 tr\u00e1i nh\u00f3m C: c\u00e2n l\u1ea7n 2.<\/p>\n

    + N\u1ebfu c\u00e2n l\u1ea7n 2 b\u1eb1ng nhau th\u00ec nh\u00f3m A c\u00f3 tr\u00e1i gi\u1ea3 v\u00e0 l\u00e0 tr\u00e1i gi\u1ea3 nh\u1eb9 h\u01a1n.<\/p>\n

    C\u00e2n 2 tr\u00e1i nh\u00f3m A: c\u00e2n l\u1ea7n 3:<\/p>\n

    N\u1ebfu c\u00e2n th\u0103ng b\u1eb1ng th\u00ec tr\u00e1i gi\u1ea3 l\u00e0 tr\u00e1i th\u1ee9 3 c\u1ee7a nh\u00f3m A. N\u1ebfu kh\u00f4ng c\u00e2n b\u1eb1ng th\u00ec tr\u00e1i b\u00ean nh\u1eb9 l\u00e0 tr\u00e1i gi\u1ea3.<\/p>\n

    + N\u1ebfu c\u00e2n l\u1ea7n 2 kh\u00f4ng b\u1eb1ng nhau th\u00ec nh\u00f3m B c\u00f3 tr\u00e1i gi\u1ea3 v\u00e0 tr\u00e1i gi\u1ea3 n\u1eb7ng h\u01a1n.<\/p>\n

    C\u00e2n 2 tr\u00e1i nh\u00f3m B: c\u00e2n l\u1ea7n 3.<\/p>\n

    N\u1ebfu c\u00e2n th\u0103ng b\u1eb1ng th\u00ec tr\u00e1i gi\u1ea3 l\u00e0 tr\u00e1i th\u1ee9 3 c\u1ee7a nh\u00f3m B, n\u1ebfu kh\u00f4ng c\u00e2n b\u1eb1ng th\u00ec tr\u00e1i b\u00ean n\u1eb7ng l\u00e0 tr\u00e1i gi\u1ea3.<\/p>\n

    <\/a>C\u00c2U 3:<\/h3>\n

    B\u00e0i gi\u1ea3i:<\/p>\n

    M\u1ed7i l\u1edbp A, B, C \u0103n h\u1ebft:<\/p>\n

    L\u1edbp C ph\u1ea3i tr\u1ea3 24 \u0111\u1ed3ng cho kg b\u00e1nh, v\u1eady 1kg b\u00e1nh tr\u1ecb gi\u00e1:<\/p>\n

    \"143_2.jpg\"<\/p>\n

    L\u1edbp A mang t\u1edbi 5kg b\u00e1nh, v\u1eady s\u1ed1 b\u00e1nh l\u1edbp A kh\u00f4ng d\u00f9ng t\u1edbi l\u00e0:<\/p>\n

    \"143_3.jpg\"<\/p>\n

    L\u1edbp B mang t\u1edbi 3 kg b\u00e1nh, v\u1eady s\u1ed1 b\u00e1nh l\u1edbp B kh\u00f4ng d\u00f9ng t\u1edbi l\u00e0:<\/p>\n

    \"143_4.jpg\"<\/p>\n

    S\u1ed1 ti\u1ec1n l\u1edbp A nh\u1eadn \u0111\u01b0\u1ee3c l\u00e0:<\/p>\n

    \"143_5.jpg\"<\/p>\n

    S\u1ed1 ti\u1ec1n l\u1edbp B nh\u1eadn \u0111\u01b0\u1ee3c l\u00e0:<\/p>\n

    \"143_6.jpg\"<\/p>\n

    \u0110\u00e1p s\u1ed1: 21 \u0111\u1ed3ng v\u00e0 3 \u0111\u1ed3ng.<\/p>\n

    <\/a>C\u00c2U 4:<\/h3>\n

    \u0110\u00e1p s\u1ed1:<\/p>\n

    H\u00e0: vi\u1ebft th\u01b0<\/p>\n

    Tu\u1ea5n: \u0111\u1ecdc s\u00e1ch<\/p>\n

    Th\u1eafng: vi\u1ebft th\u01b0<\/p>\n

    Minh: S\u1eeda \u00e1o.<\/p>\n","protected":false},"excerpt":{"rendered":"

    C\u00c2U 1: N\u0103m b\u1ea1n \u0111o\u00e1n tu\u1ed5i v\u00e0 ng\u00e0y, th\u00e1ng sinh nh\u1eadt c\u1ee7a c\u00f4 gi\u00e1o. B\u1ea1n Tu\u1ed5i Ng\u00e0y Th\u00e1ng T\u00edn 25 10 3 D\u0169ng 27 11 4 Minh 25 11 4 Trang 25 11 3 H\u01b0\u01a1ng 27 10 3 Bi\u1ebft r\u1eb1ng c\u00f3 1 b\u1ea1n \u0111o\u00e1n \u0111\u00fang ho\u00e0n to\u00e0n, c\u00f2n 4 b\u1ea1n kh\u00e1c kh\u00f4ng \u0111o\u00e1n sai ho\u00e0n […]<\/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-25543","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\/25543","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=25543"}],"version-history":[{"count":1,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/25543\/revisions"}],"predecessor-version":[{"id":25549,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/25543\/revisions\/25549"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=25543"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=25543"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=25543"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}