Tr\u00f2 ch\u01a1i b\u00e0i \u201c24 \u0111i\u1ec3m\u201d l\u00e0 lo\u1ea1i b\u00e0i ch\u01a1i \u0111\u1ea5u tr\u00ed. C\u00e1ch ch\u01a1i nh\u01b0 sau: M\u1ed7i b\u1ed9 b\u00e0i t\u00fa l\u01a1 kh\u01a1, n\u1ebfu l\u1ea5y c\u00e1c con b\u00e0i c\u00f3 s\u1ed1 A, 2, 3, 4, 5, 6, 7, 8, 9, 10 v\u1edbi c\u1ea3 b\u1ed1n lo\u1ea1i hoa th\u00ec t\u1ea5t c\u1ea3 c\u00f3 40 con b\u00e0i, con A \u0111\u01b0\u1ee3c xem l\u00e0 s\u1ed1 1. Chia \u0111\u1ec1u to\u00e0n b\u1ed9 b\u00e0i cho b\u1ed1n ng\u01b0\u1eddi ch\u01a1i. M\u1ed7i ng\u01b0\u1eddi \u00fap s\u1ed1 l\u00e1 b\u00e0i c\u1ee7a m\u00ecnh tr\u00ean b\u00e0n. Sau \u0111\u00f3 b\u1eaft \u0111\u1ea7u cu\u1ed9c ch\u01a1i, b\u1ed1n ng\u01b0\u1eddi \u0111\u1ed3ng th\u1eddi l\u1eadt m\u1ed9t l\u00e1 b\u00e0i trong s\u1ed1 b\u00e0i c\u1ee7a m\u00ecnh. Y\u00eau c\u1ea7u m\u1ed7i ng\u01b0\u1eddi ch\u01a1i c\u0103n c\u1ee9 theo s\u1ed1 c\u1ee7a l\u00e1 b\u00e0i (kh\u00f4ng k\u1ec3 hoa) ti\u1ebfn h\u00e0nh c\u1ed9ng, tr\u1eeb, nh\u00e2n, chia c\u00e1c con s\u1ed1 \u0111\u1ec3 nh\u1eadn \u0111\u01b0\u1ee3c s\u1ed1 24. Ai th\u1ef1c hi\u1ec7n xong tr\u01b0\u1edbc ng\u01b0\u1eddi \u0111\u00f3 s\u1ebd th\u1eafng. V\u00ed d\u1ee5 v\u1edbi b\u1ed1n l\u00e1 b\u00e0i: Con 4 r\u00f4, 4 c\u01a1, 3 nh\u00e9p v\u00e0 A b\u00edch. D\u00f9ng c\u00e1c c\u00e1ch sau \u0111\u00e2y s\u1ebd nh\u1eadn \u0111\u01b0\u1ee3c s\u1ed1 24: 4 x (4 +3 -1) ho\u1eb7c 3x (4+4)x<\/p>\n\n\n\n
Nh\u01b0 v\u1eady khi c\u00f3 b\u1ed1n l\u00e1 b\u00e0i xu\u1ea5t hi\u1ec7n tr\u00ean m\u1eb7t b\u00e0n th\u00ec c\u00f3 bao nhi\u00eau t\u00ecnh hu\u1ed1ng c\u00f3 th\u1ec3 th\u1ef1c hi\u1ec7n c\u00e1c ph\u00e9p t\u00ednh \u0111\u1ec3 nh\u1eadn \u0111\u01b0\u1ee3c s\u1ed1 24?<\/p>\n\n\n\n
Do kh\u00f4ng c\u1ea7n \u0111\u1ec3 \u00fd \u0111\u1ebfn lo\u1ea1i hoa c\u1ee7a c\u00e1c con b\u00e0i c\u0169ng nh\u01b0 th\u1ee9 t\u1ef1 ph\u00e2n b\u1ed1 l\u00e1 b\u00e0i tr\u00ean m\u1eb7t b\u00e0n, n\u00ean b\u00e0i to\u00e1n n\u00eau tr\u00ean th\u1ef1c t\u1ebf l\u00e0 trong c\u00e1c s\u1ed1 t\u1eeb 1 – 10, l\u1ea5y tu\u1ef3 \u00fd b\u1ed1n s\u1ed1 trong 10 s\u1ed1 th\u00e0nh t\u1eebng t\u1ed5 h\u1ee3p (cho ph\u00e9p c\u00f3 s\u1ef1 tr\u00f9ng s\u1ed1). \u0110\u1ec3 ti\u1ec7n vi\u1ec7c t\u00ednh to\u00e1n, ta c\u00f3 th\u1ec3 ch\u1ecdn c\u00e1ch x\u1eed l\u00ed nh\u00f3m s\u1ed1 theo nh\u01b0 d\u01b0\u1edbi \u0111\u00e2y: S\u1eafp x\u1ebfp c\u00e1c s\u1ed1 theo th\u1ee9 t\u1ef1 t\u1eeb nh\u1ecf \u0111\u1ebfn l\u1edbn 0, 1, 2, 3,\u2026, sau \u0111\u00f3 l\u1eadp m\u1ed9t b\u1ed9 b\u1ed1n s\u1ed1 t\u01b0\u01a1ng \u1ee9ng m\u1ed9t – m\u1ed9t \u0111\u1ec3 l\u1eadp th\u00e0nh m\u1ed9t b\u1ed9 b\u1ed1n s\u1ed1 m\u1edbi. N\u1ebfu kh\u00f4ng k\u1ec3 s\u1ef1 tr\u00f9ng l\u1eb7p c\u1ee7a c\u00e1c s\u1ed1 c\u0169ng nh\u01b0 th\u1ee9 t\u1ef1 s\u1eafp x\u1ebfp c\u00e1c s\u1ed1 trong b\u1ed9 s\u1ed1, c\u00e1c b\u1ed9 s\u1ed1 t\u1ea1o th\u00e0nh m\u1ed9t t\u1ed5 h\u1ee3p ch\u1eadp b\u1ed1n c\u1ee7a n y\u1ebfu t\u1ed1. N\u1ebfu ch\u1ecdn n = 10 nh\u01b0 \u0111i\u1ec1u ki\u1ec7n b\u00e0i to\u00e1n \u0111\u1eb7t ra th\u00ec s\u1ed1 t\u00ecnh hu\u1ed1ng theo nh\u01b0 b\u00e0i to\u00e1n \u0111\u1eb7t ra s\u1ebd l\u00e0:<\/p>\n\n\n\n
Nh\u01b0 v\u1eady trong tr\u00f2 ch\u01a1i 24 \u0111i\u1ec3m v\u1edbi 40 l\u00e1 b\u00e0i s\u1ebd l\u00e0 210 tr\u01b0\u1eddng h\u1ee3p.<\/p>\n\n\n\n
T\u1eeb kho\u00e1: T\u1ed5 h\u1ee3p.<\/p>\n\n\n\n
<\/p>\n\n\n\n\n\n\n","protected":false},"excerpt":{"rendered":"
Tr\u00f2 ch\u01a1i b\u00e0i \u201c24 \u0111i\u1ec3m\u201d l\u00e0 lo\u1ea1i b\u00e0i ch\u01a1i \u0111\u1ea5u tr\u00ed. C\u00e1ch ch\u01a1i nh\u01b0 sau: M\u1ed7i b\u1ed9 b\u00e0i t\u00fa l\u01a1 kh\u01a1, n\u1ebfu l\u1ea5y c\u00e1c con b\u00e0i c\u00f3 s\u1ed1 A, 2, 3, 4, 5, 6, 7, 8, 9, 10 v\u1edbi c\u1ea3 b\u1ed1n lo\u1ea1i hoa th\u00ec t\u1ea5t c\u1ea3 c\u00f3 40 con b\u00e0i, con A \u0111\u01b0\u1ee3c xem l\u00e0 […]<\/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":[15,9],"tags":[],"class_list":["post-7583","post","type-post","status-publish","format-standard","hentry","category-hoi-dap-khoa-hoc","category-toan-hoc"],"_links":{"self":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/7583","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=7583"}],"version-history":[{"count":0,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/7583\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=7583"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=7583"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=7583"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}