K\u00e9p l\u1ec7ch, k\u00e9p b\u1eb1ng, s\u00e1t k\u00e9p v\u00e0 k\u00e9p \u00e2m l\u00e0 nh\u1eefng thu\u1eadt ng\u1eef ch\u1ec9 <\/em><\/span>b\u1ed9 s\u1ed1 k\u00e9p<\/em><\/strong><\/span> kh\u00e1 quen thu\u1ed9c trong l\u00e0ng l\u00f4 \u0111\u1ec1. Ch\u00fang l\u00e0 nh\u1eefng b\u1ed9 s\u1ed1 c\u1ea7n hi\u1ec3u r\u00f5 khi ch\u01a1i l\u00f4. Th\u1ebf nh\u01b0ng th\u1ef1c t\u1ebf l\u1ea1i c\u00f3 kh\u00f4ng \u00edt ng\u01b0\u1eddi kh\u00f4ng bi\u1ebft b\u1ed9 s\u1ed1 k\u00e9p g\u1ed3m c\u00e1c s\u1ed1 n\u00e0o v\u00e0 c\u00f3 bao nhi\u00eau con, \u0111\u1eb7c bi\u1ec7t l\u00e0 v\u1edbi nh\u1eefng ng\u01b0\u1eddi m\u1edbi ch\u01a1i. Trong b\u00e0i vi\u1ebft n\u00e0y s\u1ebd c\u00f9ng b\u1ea1n \u0111\u1ecdc gi\u1ea3i \u0111\u00e1p t\u1ea5t t\u1ea7n t\u1eadt v\u1ec1 b\u1ed9 s\u1ed1 k\u00e9p.<\/em><\/span><\/p>\n M\u1ed9t trong nh\u1eefng ki\u1ec3u b\u1ed9 s\u1ed1 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng t\u1eeb r\u1ea5t l\u00e2u \u0111\u1eddi v\u00e0 r\u1ed9ng r\u00e3i trong l\u00f4 \u0111\u1ec1 ch\u00ednh l\u00e0 b\u1ed9 s\u1ed1 k\u00e9p.T\u1eeb t\u00ean g\u1ecdi k\u00e9p b\u1eb1ng, c\u00f3 l\u1ebd \u0111\u00e2u \u0111\u00f3 b\u1ea1n c\u0169ng m\u01b0\u1eddng t\u01b0\u1ee3ng ra r\u1eb1ng k\u00e9p b\u1eb1ng hay b\u1ed9 s\u1ed1 k\u00e9p ch\u00ednh l\u00e0 t\u1ea5t c\u1ea3 nh\u1eefng s\u1ed1 g\u1ed3m 2 ch\u1eef s\u1ed1 gi\u1ed1ng nhau. C\u1ee5 th\u1ec3 c\u00f3 10 b\u1ed9 s\u1ed1 k\u00e9p b\u1eb1ng, \u0111\u00f3 l\u00e0: 00, 11, …, 88, 99.<\/span><\/p>\n D\u1ef1a v\u00e0o k\u00e9p b\u1eb1ng, b\u1eb1ng nh\u1eefng c\u00e1ch kh\u00e1c nhau, ng\u01b0\u1eddi ta m\u1edf r\u1ed9ng ra \u0111\u01b0\u1ee3c c\u00e1c b\u1ed9 s\u1ed1 k\u00e9p l\u1ec7ch, s\u00e1t k\u00e9p v\u00e0 k\u00e9p \u00e2m v\u00ec s\u1ef1 c\u1ea7n thi\u1ebft \u0111\u1ec3 ph\u00e1t tri\u1ec3n s\u00e2n ch\u01a1i l\u00f4 \u0111\u1ec1. Trong ph\u1ea7n ti\u1ebfp theo, ch\u00fang ta s\u1ebd c\u00f9ng t\u00ecm hi\u1ec3u v\u1ec1 nh\u1eefng b\u1ed9 k\u00e9p kh\u00e1c.<\/span><\/p>\n B\u1ed9 k\u00e9p l\u1ec7ch \u0111\u01b0\u1ee3c m\u1edf r\u1ed9ng d\u1ef1a tr\u00ean \u0111\u1ecbnh ngh\u0129a b\u00f3ng<\/span>. C\u00e1c c\u1eb7p b\u00f3ng bao g\u1ed3m: 0 – 5, 1 – 6, 2 – 7, 3 – 8, 4 – 9. M\u1ed9t quy t\u1eafc \u0111\u01a1n gi\u1ea3n \u0111\u1ec3 nh\u1edb l\u00e2u \u0111\u00f3 l\u00e0: c\u00e1c s\u1ed1 l\u00e0 b\u00f3ng c\u1ee7a nhau khi h\u00e0ng \u0111\u01a1n v\u1ecb h\u01a1n k\u00e9m nhau l\u00e0 5. Nh\u01b0 v\u1eady, c\u00e1c s\u1ed1 l\u00e0 b\u00f3ng c\u1ee7a nhau n\u1ebfu c\u00e1c s\u1ed1 \u0111\u00f3 c\u00f3 1 ch\u1eef s\u1ed1 gi\u1ed1ng nhau v\u00e0 s\u1ed1 c\u00f2n l\u1ea1i l\u00e0 b\u00f3ng c\u1ee7a nhau ho\u1eb7c c\u1ea3 2 ch\u1eef s\u1ed1 trong c\u00e1c s\u1ed1 \u0111\u1ec1u l\u00e0 c\u1eb7p b\u00f3ng.\u00a0<\/span><\/p>\n \u0110\u1ec3 d\u1ec5 hi\u1ec3u, b\u1ea1n xem v\u00ed d\u1ee5 sau:<\/span><\/p>\n K\u00e9p l\u1ec7ch l\u00e0 c\u00e1c s\u1ed1 b\u00f3ng c\u1ee7a k\u00e9p b\u1eb1ng. \u0110\u01a1n gi\u1ea3n h\u01a1n, k\u00e9p l\u1ec7ch l\u00e0 s\u1ed1 g\u1ed3m 2 ch\u1eef s\u1ed1 l\u00e0 b\u00f3ng c\u1ee7a nhau. Ch\u1eb3ng h\u1ea1n, k\u00e9p l\u1ec7ch 05 l\u00e0 b\u00f3ng c\u1ee7a k\u00e9p b\u1eb1ng 00, k\u00e9p l\u1ec7ch 16 l\u00e0 b\u00f3ng c\u1ee7a k\u00e9p b\u1eb1ng 11, \u2026 k\u00e9p l\u1ec7ch 94 l\u00e0 b\u00f3ng c\u1ee7a k\u00e9p b\u1eb1ng 99. V\u1eady, ta c\u00f3 t\u1ea5t c\u1ea3 l\u00e0 10 b\u1ed9 k\u00e9p l\u1ec7ch t\u01b0\u01a1ng \u1ee9ng v\u1edbi 10 b\u1ed9 k\u00e9p b\u1eb1ng, g\u1ed3m: 05 \u2013 50 \u2013 16 \u2013 61 \u2013 27 \u2013 72 \u2013 38 \u2013 83 \u2013 49 \u2013 94.<\/span><\/p>\n S\u00e1t k\u00e9p l\u00e0 c\u00e1c s\u1ed1 li\u1ec1n tr\u01b0\u1edbc ho\u1eb7c li\u1ec1n sau c\u00e1c s\u1ed1 k\u00e9p b\u1eb1ng. S\u00e1t k\u00e9p ch\u00ednh l\u00e0 s\u1ed1 h\u01a1n ho\u1eb7c k\u00e9m s\u1ed1 k\u00e9p b\u1eb1ng 1 \u0111\u01a1n v\u1ecb. \u1ede \u0111\u00e2y, ch\u00fang ta c\u00f3 2 b\u1ed9 k\u00e9p l\u00e0 k\u00e9p b\u1eb1ng v\u00e0 k\u00e9p l\u1ec7ch, do \u0111\u00f3 s\u00e1t k\u00e9p c\u0169ng \u0111\u01b0\u1ee3c ph\u00e2n ra 2 lo\u1ea1i l\u00e0 s\u00e1t k\u00e9p b\u1eb1ng, s\u00e1t k\u00e9p l\u1ec7ch.<\/span><\/p>\n S\u00e1t k\u00e9p b\u1eb1ng c\u00f2n \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 \u00e1p k\u00e9p b\u1eb1ng, l\u00e0 c\u00e1c s\u1ed1 li\u1ec1n tr\u01b0\u1edbc ho\u1eb7c li\u1ec1n sau c\u00e1c s\u1ed1 trong b\u1ed9 k\u00e9p b\u1eb1ng. M\u1ed7i b\u1ed9 k\u00e9p b\u1eb1ng c\u00f3 10 s\u1ed1, m\u1ed7i s\u1ed1 n\u00e0y s\u1ebd g\u1ed3m 1 s\u1ed1 li\u1ec1n tr\u01b0\u1edbc v\u00e0 1 s\u1ed1 li\u1ec1n sau (tr\u1eeb 00 ch\u1ec9 c\u00f3 s\u1ed1 01 li\u1ec1n sau v\u00e0 s\u1ed1 99 ch\u1ec9 c\u00f3 s\u1ed1 98 li\u1ec1n tr\u01b0\u1edbc). Nh\u01b0 v\u1eady, ta s\u1ebd c\u00f3 18 s\u1ed1 trong b\u1ed9 s\u00e1t k\u00e9p b\u1eb1ng, g\u1ed3m: (00) 01, 10 (11) 12, 21 (22) 23, 32 (33) 34, 43 (44) 45, 54 (55) 56, 65, (66) 67, 76 (77) 78, 87 (88) 89, 98 (99).\u00a0<\/span><\/p>\n Ch\u00fa th\u00edch:<\/u><\/span> C\u00e1c s\u1ed1 trong d\u1ea5u ngo\u1eb7c l\u00e0 s\u1ed1 k\u00e9p b\u1eb1ng \u0111\u1ec3 b\u1ea1n d\u1ec5 h\u00ecnh dung.<\/span><\/p>\n Ngo\u00e0i ra, m\u1ed9t s\u1ed1 nh\u00e0 c\u00e1i c\u00f2n c\u00f3 th\u00eam c\u1eb7p s\u1ed1 s\u00e1t k\u00e9p b\u1eb1ng l\u00e0 09 v\u00e0 90. Do \u0111\u00f3, b\u1ea1n c\u1ea7n h\u1ecfi k\u1ef9 tr\u01b0\u1edbc v\u1ec1 vi\u1ec7c c\u00f3 hay kh\u00f4ng c\u00f3 c\u1eb7p 09, 90 \u0111\u1ec3 thu\u1eadn ti\u1ec7n khi ch\u01a1i l\u00f4 \u0111\u1ec1 nh\u00e9.<\/span><\/p>\n S\u00e1t k\u00e9p l\u1ec7ch c\u00f2n \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 \u00e1p k\u00e9p l\u1ec7ch, l\u00e0 c\u00e1c s\u1ed1 li\u1ec1n tr\u01b0\u1edbc ho\u1eb7c li\u1ec1n sau c\u00e1c s\u1ed1 trong b\u1ed9 s\u1ed1 k\u00e9p l\u1ec7ch. \u1ede \u0111\u00e2y, ch\u00fang ta c\u0169ng c\u00f3 20 s\u1ed1 trong b\u1ed9 s\u00e1t k\u00e9p l\u1ec7ch. C\u1ee5 th\u1ec3 l\u00e0: 04 (05) 06, 49 (50) 51, 15 (16) 17, 60 (61) 62, 26 (27) 28, 71 (72) 73, 37 (38) 39, 82 (83) 84, 48 (49) 50, 93 (94) 95.<\/span><\/p>\n Ch\u00fa th\u00edch:<\/u><\/span> C\u00e1c s\u1ed1 trong d\u1ea5u ngo\u1eb7c l\u00e0 s\u1ed1 k\u00e9p l\u1ec7ch \u0111\u1ec3 b\u1ea1n d\u1ec5 h\u00ecnh dung.<\/span><\/p>\n Ngo\u00e0i b\u00f3ng d\u01b0\u01a1ng, ng\u01b0\u1eddi ta c\u00f2n m\u1edf r\u1ed9ng ra b\u00f3ng \u00e2m, t\u1eeb \u0111\u00f3 ph\u00e1t tri\u1ec3n n\u00ean c\u00e1c b\u1ed9 s\u1ed1 k\u00e9p \u00e2m.<\/span><\/span><\/p>\n C\u1eb7p b\u00f3ng \u00e2m c\u00f3: 0 v\u00e0 7, 1 v\u00e0 4, 2 v\u00e0 9, 3 v\u00e0 6, 5 v\u00e0 8. S\u1ed1 n\u00e0y \u0111\u01b0\u1ee3c xem l\u00e0 b\u00f3ng \u00e2m c\u1ee7a s\u1ed1 kia v\u00e0 ng\u01b0\u1ee3c l\u1ea1i.<\/span><\/p>\n \u0110\u1ec3 d\u1ec5 hi\u1ec3u, b\u1ea1n xem v\u00ed d\u1ee5 sau:<\/span><\/p>\n K\u00e9p \u00e2m l\u00e0 c\u00e1c s\u1ed1 g\u1ed3m 2 ch\u1eef s\u1ed1 l\u00e0 k\u00e9p \u00e2m c\u1ee7a nhau. T\u1ea5t c\u1ea3 c\u00f3 10 s\u1ed1 trong b\u1ed9 k\u00e9p \u00e2m g\u1ed3m: 07 – 70 – 14 – 41 – 29 – 92 – 36 – 63 – 58 – 85.<\/span><\/p>\n \u0110\u1ec3 ch\u1eafc ch\u1eafn h\u01a1n trong vi\u1ec7c \u0111\u00e1nh con s\u1ed1 n\u00e0o, c\u00e1c b\u1ea1n c\u00f3 th\u1ec3 xem ng\u00e0y ch\u01a1i theo phong th\u1ee7y th\u1ec3 xem ng\u00e0y \u0111\u00f3 con l\u00f4 n\u00e0o s\u1ebd c\u00f3 kh\u1ea3 n\u0103ng v\u1ec1 cao h\u01a1n.\u00a0<\/span><\/p>\n Tr\u00ean \u0111\u00e2y, .\u0111\u00e3 chia s\u1ebb to\u00e0n b\u1ed9 c\u00e1c ki\u1ebfn th\u1ee9c li\u00ean quan \u0111\u1ebfn <\/span>b\u1ed9 s\u1ed1 k\u00e9p<\/strong><\/span> c\u0169ng nh\u01b0 c\u00e1c phi\u00ean b\u1ea3n m\u1edf r\u1ed9ng t\u1eeb n\u00f3. Mong r\u1eb1ng b\u00e0i vi\u1ebft s\u1ebd h\u1eefu \u00edch cho b\u1ea1n khi ch\u01a1i l\u00f4 \u0111\u1ec1.<\/span><\/p>\n<\/div>\n1. K\u00e9p b\u1eb1ng<\/strong><\/span><\/h2>\n
2. B\u1ed9 s\u1ed1 k\u00e9p m\u1edf r\u1ed9ng<\/strong><\/span><\/h2>\n
3. K\u00e9p l\u1ec7ch<\/strong><\/span><\/h2>\n
B\u00f3ng d\u01b0\u01a1ng<\/em><\/strong><\/span><\/h3>\n
\n
K\u00e9p l\u1ec7ch g\u1ed3m c\u00e1c s\u1ed1 n\u00e0o?<\/em><\/strong><\/span><\/h3>\n
4. S\u00e1t k\u00e9p<\/strong><\/span><\/h2>\n
S\u00e1t k\u00e9p b\u1eb1ng<\/em><\/strong><\/span><\/h3>\n
S\u00e1t k\u00e9p l\u1ec7ch<\/em><\/strong><\/span><\/h3>\n
5. K\u00e9p \u00e2m<\/strong><\/span><\/h2>\n
B\u00f3ng \u00e2m<\/em><\/strong><\/span><\/h3>\n
\n
K\u00e9p \u00e2m<\/em><\/strong><\/span><\/h3>\n
6. \u0110\u1ec1 v\u1ec1 k\u00e9p h\u00f4m sau \u0111\u00e1nh con g\u00ec?<\/strong><\/span><\/h2>\n
\u0110\u1ec1 v\u1ec1 k\u00e9p b\u1eb1ng<\/em><\/strong><\/span><\/h3>\n
\n
c\u1ea7u \u0111\u1eb9p d\u00e0nh cho mi\u1ec1n b\u1eafc v\u00edp<\/span><\/strong><\/h3>\n