16ChuyenDeToan5

["Chuy\u00ean \u0111\u1ec1 b\u1ed3i d\u01b0\u1ee1ng HS l\u1edbp 5. a) T\u00ednh xem 2 t\u1ec9nh A v\u00e0 B c\u00e1ch nhau bao nhi\u00eau ki - l\u00f4 - m\u00e9t? b) H\u00e3y t\u00ednh xem trung b\u00ecnh m\u1ed7i gi\u1edd \u00f4 t\u00f4 ph\u1ea3i ch\u1ea1y bao nhi\u00eau ki - l\u00f4 - m\u00e9t \u0111\u1ec3 \u0111\u1ebfn B \u0111\u00fang 16 gi\u1edd? 3 B\u00e0i 4: M\u1ed9t \u00f4 t\u00f4 ph\u1ea3i ch\u1ea1y t\u1eeb A \u0111\u1ebfn B. Sau khi ch\u1ea1y \u0111\u1ee3c 1 gi\u1edd th\u00ec \u00f4 t\u00f4 gi\u1ea3m v\u1eadn t\u1ed1c ch\u1ec9 c\u00f2n b\u1eb1ng 5 v\u1eadn t\u1ed1c ban \u0111\u1ea7u. V\u00ec th\u1ebf, \u00f4 t\u00f4 \u0111\u1ebfn B ch\u1eadm m\u1ea5t 2 gi\u1edd. N\u1ebfu t\u1eeb A, sau khi ch\u1ea1y \u0111\u1ee3c 1 gi\u1edd, \u00f4 t\u00f4 ch\u1ea1y th\u00eam 50km n\u1eefa r\u1ed3i m\u1edbi gi\u1ea3m v\u1eadn t\u1ed1c th\u00ec \u00f4 t\u00f4 \u0111\u1ebfn B ch\u1ec9 ch\u1eadm 1 gi\u1edd 20 ph\u00fat. T\u00ednh qu\u00e3ng \u0111\u1eddng AB. B\u00e0i 5: M\u1ed9t \u00f4 t\u00f4 ph\u1ea3i \u0111i t\u1eeb A qua B \u0111\u1ebfn C m\u1ea5t 8 gi\u1edd. Th\u1eddi gian \u0111i t\u1eeb A \u0111\u1ebfn B nhi\u1ec1u g\u1ea5p 3 l\u1ea7n \u0111i t\u1eeb B \u0111\u1ebfn C v\u00e0 qu\u00e3ng \u0111\u1eddng t\u1eeb A \u0111\u1ebfn B d\u00e0i h\u01a1n qu\u00e3ng \u0111\u1eddng t\u1eeb B \u0111\u1ebfn C l\u00e0 130km. Bi\u1ebft r\u1eb1ng, mu\u1ed1n \u0111i \u0111\u1ee3c \u0111\u00fang th\u1eddi gian \u0111\u00e3 \u0111\u1ecbnh t\u1eeb B \u0111\u1ebfn C \u00f4 t\u00f4 ph\u1ea3i t\u0103ng t\u1ed1c th\u00eam v\u1eadn t\u1ed1c 5km m\u1ed9t gi\u1edd. H\u1ecfi qu\u00e3ng \u0111\u1eddng t\u1eeb A \u0111\u1ebfn C d\u00e0i bao nhi\u00eau ki - l\u00f4 - m\u00e9t? B\u00e0i 6: C\u00f9ng m\u1ed9t l\u00fac, c\u00f3 m\u1ed9t \u00f4 t\u00f4 \u0111i t\u1eeb t\u1ec9nh A \u0111\u1ebfn t\u1ec9nh B v\u1edbi v\u1eadn t\u1ed1c 50 km\/gi\u1edd v\u00e0 m\u1ed9t xe m\u00e1y \u0111i t\u1eeb t\u1ec9nh B \u0111\u1ebfn t\u1ec9nh A v\u1edbi v\u1eadn t\u1ed1c 30 km\/gi\u1edd. \u00d4 t\u00f4 v\u00e0 xe m\u00e1y g\u1eb7p nhau sau 2 gi\u1edd 30 ph\u00fat. a) T\u00ednh qu\u00e3ng \u0111\u1eddng AB. b) Khi \u00f4 t\u00f4 \u0111\u1ebfn B th\u00ec xe m\u00e1y c\u00f2n c\u00e1ch A bao nhi\u00eau ki - l\u00f4 - m\u00e9t? c) T\u00ednh kho\u1ea3ng c\u00e1ch gi\u1eefa \u00f4 t\u00f4 v\u00e0 xe m\u00e1y sau khi c\u00f9ng \u0111i \u0111\u1ee3c 1 gi\u1edd 30 ph\u00fat. B\u00e0i 7: T\u1eeb 2 t\u1ec9nh A v\u00e0 B c\u00e1ch nhau 396km, c\u00f3 2 ng\u1eddi kh\u1edfi h\u00e0nh c\u00f9ng m\u1ed9t l\u00fac v\u00e0 \u0111i ng\u1ee3c chi\u1ec1u v\u1edbi nhau. Khi ng\u1eddi th\u1ee9 nh\u1ea5t \u0111i \u0111\u1ee3c 216km th\u00ec 2 ng\u1eddi g\u1eb7p nhau. L\u00fac \u0111\u00f3 h\u1ecd \u0111\u00e3 \u0111i h\u1ebft m\u1ed9t s\u1ed1 ng\u00e0y \u0111\u00fang b\u1eb1ng hi\u1ec7u c\u1ee7a s\u1ed1 ki - l\u00f4 - m\u00e9t m\u00e0 2 ng\u1eddi \u0111i \u0111\u1ee3c trong m\u1ed9t ng\u00e0y. H\u00e3y t\u00ednh xem m\u1ed7i ng\u1eddi \u0111i \u0111\u1ee3c bao nhi\u00eau ki - l\u00f4 - m\u00e9t trong m\u1ed9t ng\u00e0y? (v\u1eadn t\u1ed1c c\u1ee7a m\u1ed7i ng\u1eddi kh\u00f4ng thay \u0111\u1ed5i tr\u00ean \u0111- \u1eddng \u0111i). B\u00e0i 8: Bi\u00ean Ho\u00e0 c\u00e1ch V\u0169ng T\u00e0u 100km. L\u00fac 8 gi\u1edd s\u00e1ng m\u1ed9t s\u00f4 t\u00f4 \u0111i t\u1eeb Bi\u00ean Ho\u00e0 \u0111\u1ebfn V\u0169ng T\u00e0u v\u1edbi v\u1eadn t\u1ed1c 50 km\/gi\u1edd. T\u1edbi V\u0169ng T\u00e0u, xe ngh\u1ec9 45 ph\u00fat r\u1ed3i quay tr\u1edf v\u1ec1 Bi\u00ean Ho\u00e0. L\u00fac 8 gi\u1edd 15 ph\u00fat, m\u1ed9t chi\u1ebfc xe \u0111\u1ea1p \u0111i t\u1eeb Bi\u00ean Ho\u00e0 \u0111\u1ebfn V\u0169ng T\u00e0u v\u1edbi v\u1eadn t\u1ed1c 10 km\/gi\u1edd. H\u1ecfi: a) Hai xe g\u1eb7p nhau l\u00fac m\u1ea5y gi\u1edd? b) Ch\u1ed7 g\u1eb7p nhau c\u00e1ch Bi\u00ean Ho\u00e0 bao nhi\u00eau ki - l\u00f4 - m\u00e9t? B\u00e0i 9: Hai anh em xu\u1ea5t ph\u00e1t c\u00f9ng m\u1ed9t l\u00fac \u1edf v\u1ea1ch \u0111\u00edch v\u00e0 ch\u1ea1y ng\u1ee3c chi\u1ec1u nhau tr\u00ean m\u1ed9t \u0111\u1eddng \u0111ua v\u00f2ng quanh s\u00e2n v\u1eadn \u0111\u1ed9ng. Anh ch\u1ea1y nhanh h\u01a1n em v\u00e0 khi ch\u1ea1y \u0111\u1ee3c 900m th\u00ec g\u1eb7p em l\u1ea7n th\u1ee9 nh\u1ea5t. H\u1ecd ti\u1ebfp t\u1ee5c ch\u1ea1y nh v\u1eady v\u00e0 g\u1eb7p nhau l\u1ea7n th\u1ee9 hai, l\u1ea7n th\u1ee9 ba. \u0110\u00fang l\u1ea7n g\u1eb7p nhau th ba th\u00ec h\u1ecd d\u1eebng l\u1ea1i v\u00e0 th\u1ea5y d\u1eebng l\u1ea1i \u1edf \u0111\u00fang v\u1ea1ch xu\u1ea5t ph\u00e1t ban \u0111\u1ea7u. T\u00ecm v\u1eadn t\u1ed1c c\u1ee7a m\u1ed7i ng\u1eddi, bi\u1ebft ng\u1eddi em ch\u1ea1y t\u1ea5t c\u1ea3 m\u1ea5t 9 ph\u00fat. B\u00e0i 10: M\u1ed9t \u00f4 t\u00f4 d\u1ef1 ki\u1ebfn \u0111i t\u1eeb A \u0111\u1ebfn B v\u1edbi v\u1eadn t\u1ed1c 45 km\/gi\u1edd \u0111\u1ec3 \u0111\u1ebfn B l\u00fac 11 gi\u1edd. Do tr\u1eddi ma, \u0111\u1eddng tr\u01a1n, \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o an to\u00e0n giao th\u00f4ng n\u00ean m\u1ed7i gi\u1edd xe ch\u1ec9 \u0111i \u0111\u1ee3c 35km v\u00e0 \u0111\u1ebfn B ch\u1eadm m\u1ea5t 30 ph\u00fat so v\u1edbi d\u1ef1 ki\u1ebfn. T\u00ednh qu\u00e3ng \u0111\u1eddng AB. B\u00e0i 11: An v\u00e0 B\u00ecnh \u0111i b\u1ed9 t\u1eeb A \u0111\u1ebfn B v\u00e0 b\u1eaft \u0111\u1ea7u \u0111i c\u00f9ng m\u1ed9t l\u00fac. Trong n\u1eeda th\u1eddi gian \u0111\u1ea7u c\u1ee7a m\u00ecnh, An \u0111i v\u1edbi v\u1eadn t\u1ed1c 5 km\/gi\u1edd, trong n\u1eeda th\u1eddi gian sau c\u1ee7a m\u00ecnh, An \u0111i v\u1edbi v\u1eadn t\u1ed1c 4 km\/gi\u1edd. Trong n\u1eeda qu\u00e3ng \u0111\u1eddng \u0111\u1ea7u c\u1ee7a m\u00ecnh, B\u00ecnh \u0111i v\u1edbi v\u1eadn t\u1ed1c 4 km\/gi\u1edd v\u00e0 trong n\u1eeda qu\u00e3ng \u0111\u1eddng sau B\u00ecnh \u0111i v\u1edbi v\u1eadn t\u1ed1c 5 km\/gi\u1edd. H\u1ecfi ai \u0111\u1ebfn B tr\u1edbc? B\u00e0i 12: Hai ng\u1eddi \u0111i xe \u0111\u1ea1p ng\u1ee3c chi\u1ec1u nhau c\u00f9ng kh\u1edfi h\u00e0nh m\u1ed9t l\u00fac. Ng\u1eddi th\u1ee9 nh\u1ea5t \u0111i t\u1eeb A, ng\u1eddi th\u1ee9 2 \u0111i t\u1eeb B v\u00e0 \u0111i nhanh h\u01a1n ng\u1eddi th\u1ee9 nh\u1ea5t. H\u1ecd g\u1eb7p nhau c\u00e1ch A 6km v\u00e0 ti\u1ebfp t\u1ee5c \u0111i kh\u00f4ng ngh\u1ec9. Sau khi g\u1eb7p nhau ng\u1eddi th\u1ee9 nh\u1ea5t \u0111i t\u1edbi B th\u00ec quay tr\u1edf l\u1ea1i v\u00e0 ng\u1eddi th\u1ee9 2 \u0111i \u0111\u1ebfn A c\u0169ng quay tr\u1edf l\u1ea1i. H\u1ecd g\u1eb7p nhau l\u1ea7n th\u1ee9 2 c\u00e1ch B 4km. Em h\u00e3y t\u00ecm xem qu\u00e3ng \u0111\u1eddng AB d\u00e0i bao nhi\u00eau ki - l\u00f4 - m\u00e9t? B\u00e0i 13: M\u1ed9t ng\u1eddi \u0111i b\u1ed9 qua m\u1ed9t c\u00e1i d\u1ed1c g\u1ed3m 2 \u0111o\u1ea1n l\u00ean xu\u1ed1ng d\u00e0i b\u1eb1ng nhau. L\u00fac l\u00ean d\u1ed1c, anh \u0111i v\u1edbi v\u1eadn t\u1ed1c 2 km\/gi\u1edd. L\u00fac xu\u1ed1ng d\u1ed1c, anh \u0111i v\u1edbi v\u1eadn t\u1ed1c 6 km\/gi\u1edd. Th\u1eddi gian ng\u1eddi \u1ea5y l\u00ean d\u1ed1c v\u00e0 xu\u1ed1ng d\u1ed1c h\u1ebft t\u1ea5t c\u1ea3 50 ph\u00fat 24 gi\u00e2y. T\u00ecm \u0111\u1eddng d\u00e0i t\u1eeb ch\u00e2n d\u1ed1c l\u00ean \u0111\u1ec9nh d\u1ed1c. 2 B\u00e0i 14: M\u1ed9t chi\u1ebfc \u00f4 t\u00f4 \u0111i qua m\u1ed9t c\u00e1i \u0111\u00e8o g\u1ed3m 2 \u0111o\u1ea1n AB v\u00e0 BC. \u0110o\u1ea1n AB d\u00e0i b\u1eb1ng 3 \u0111o\u1ea1n BC. \u00d4 t\u00f4 ch\u1ea1y l\u00ean \u0111\u00e8o theo \u0111o\u1ea1n AB v\u1edbi v\u1eadn t\u1ed1c 30 km\/gi\u1edd v\u00e0 xu\u1ed1ng \u0111\u00e8o theo \u0111o\u1ea1n BC v\u1edbi v\u1eadn t\u1ed1c 60 km\/gi\u1edd. Th\u1eddi gian \u00f4 t\u00f4 \u0111i t\u1eeb A \u0111\u1ebfn C l\u00e0 7 ph\u00fat. T\u00ecm c\u00e1c qu\u00e3ng \u0111\u1eddng AB, BC. 50","Chuy\u00ean \u0111\u1ec1 b\u1ed3i d\u01b0\u1ee1ng HS l\u1edbp 5. B\u00e0i 15: Qu\u00e3ng \u0111\u1eddng t\u1eeb A \u0111\u1ebfn B g\u1ed3m m\u1ed9t \u0111o\u1ea1n l\u00ean d\u1ed1c v\u00e0 m\u1ed9t \u0111o\u1ea1n xu\u1ed1ng d\u1ed1c. M\u1ed9t ng\u1eddi \u0111i t\u1eeb A \u0111\u1ebfn B h\u1ebft 21 ph\u00fat, r\u1ed3i tr\u1edf v\u1ec1 t\u1eeb B \u0111\u1ebfn A h\u1ebft 24 ph\u00fat. H\u00e3y t\u00ednh \u0111o\u1ea1n \u0111\u1eddng AB, bi\u1ebft r\u1eb1ng v\u1eadn t\u1ed1c ng\u1eddi \u0111\u00f3 khi l\u00ean d\u1ed1c l\u00e0 2,5 km\/gi\u1edd v\u00e0 khi xu\u1ed1ng d\u1ed1c l\u00e0 5 km\/gi\u1edd. B\u00e0i 16: M\u1ed9t ng\u1eddi \u0111i b\u1ed9 t\u1eeb A \u0111\u1ebfn B r\u1ed3i tr\u1edf v\u1ec1 A h\u1ebft t\u1ea5t c\u1ea3 3 gi\u1edd 41 ph\u00fat. \u0110\u1eddng t\u1eeb A \u0111\u1ebfn B l\u00fac \u0111\u1ea7u l\u00e0 xu\u1ed1ng d\u1ed1c, sau \u0111\u00f3 l\u00e0 \u0111\u1eddng n\u1eb1m ngang r\u1ed3i l\u1ea1i l\u00ean d\u1ed1c. H\u1ecfi qu\u00e3ng \u0111\u1eddng n\u1eb1m ngang d\u00e0i bao nhi\u00eau ki - l\u00f4 - m\u00e9t? Bi\u1ebft r\u1eb1ng v\u1eadn t\u1ed1c khi l\u00ean d\u1ed1c l\u00e0 4 km\/gi\u1edd, khi xu\u1ed1ng d\u1ed1c l\u00e0 6 km\/gi\u1edd, khi \u0111\u1eddng n\u1eb1m ngang l\u00e0 5 km\/gi\u1edd v\u00e0 kho\u1ea3ng c\u00e1ch AB l\u00e0 9km. B\u00e0i 17: M\u1ed9t \u0111o\u00e0n h\u1ecdc sinh \u0111i t\u1eeb A qua B \u0111\u1ebfn C \u0111\u1ec3 c\u1eafm tr\u1ea1i. Sau khi \u0111o\u00e0n \u0111i qua \u0111o\u1ea1n AB m\u1ea5t 2 gi\u1edd 30 ph\u00fat th\u00ec h\u1ecd t\u0103ng v\u1eadn t\u1ed1c th\u00eam m\u1ed7i gi\u1edd 1km \u0111\u1ec3 \u0111\u1ebfn C \u0111\u00fang quy \u0111\u1ecbnh. T\u00ednh qu\u00e3ng \u0111\u1eddng AC, bi\u1ebft r\u1eb1ng \u0111o\u1ea1n AB d\u00e0i h\u01a1n \u0111o\u1ea1n BC l\u00e0 0,5km v\u00e0 \u0111i \u0111o\u1ea1n \u0111\u1eddng BC h\u1ebft 2 gi\u1edd. B\u00e0i 18: M\u1ed9t ng\u1eddi \u0111i qu\u00e3ng \u0111\u1eddng 63km. L\u00fac \u0111\u1ea7u \u0111i b\u1ed9 5km\/gi\u1edd, l\u00fac sau \u0111i xe \u0111\u1ea1p v\u1edbi v\u1eadn t\u1ed1c 12km\/gi\u1edd. T\u00ednh th\u1eddi gian \u0111i xe \u0111\u1ea1p, \u0111i b\u1ed9. B\u00e0i 19: L\u00fac 7 gi\u1edd s\u00e1ng, Hu\u1ec7 kh\u1edfi h\u00e0nh t\u1eeb H\u00f3c M\u00f4n \u0111\u1ebfn C\u1ee7 Chi d\u1ef1 \u0111\u1ecbnh v\u00e0o l\u00fac 8 gi\u1edd 30 ph\u00fat. Nhng 2 \u0111i \u0111\u1ee3c 3 qu\u00e3ng \u0111\u1eddng th\u00ec gi\u1ea3m v\u1eadn t\u1ed1c m\u1ea5t 1 4 v\u1eadn t\u1ed1c ban \u0111\u1ea7u. H\u00e3y t\u00ednh xem Hu\u1ec7 \u0111\u1ebfn C\u1ee7 Chi l\u00fac m\u1ea5y gi\u1edd? B\u00e0i 20: T\u1ec9nh A c\u00e1ch t\u1ec9nh B 200km, m\u1ed9t xe honda kh\u1edfi h\u00e0nh t\u1eeb A \u0111\u1ebfn B, m\u1ed9t xe \u0111\u1ea1p m\u00e1y \u0111i t\u1eeb B \u0111\u1ebfn A. Hai xe c\u00f9ng kh\u1edfi h\u00e0nh c\u00f9ng m\u1ed9t l\u00fac \u0111i ng\u1ee3c chi\u1ec1u nhau v\u00e0 g\u1eb7p nhau c\u00e1ch B 75km. N\u1ebfu xe \u0111\u1ea1p m\u00e1y \u0111i tr\u1edbc 1 gi\u1edd 12 ph\u00fat th\u00ec h\u1ecd s\u1ebd g\u1eb7p nhau c\u00e1ch B 97,5km. T\u00ednh v\u1eadn t\u1ed1c m\u1ed7i xe. B\u00e0i 21: M\u1ed9t ng\u1eddi \u0111i xe \u0111\u1ea1p v\u1edbi v\u1eadn t\u1ed1c 12 km\/gi\u1edd v\u00e0 m\u1ed9t \u00f4 t\u00f4 \u0111i v\u1edbi v\u1eadn t\u1ed1c 28 km\/gi\u1edd c\u00f9ng kh\u1edfi h\u00e0nh l\u00fac 6 gi\u1edd t\u1eeb \u0111\u1ecba \u0111i\u1ec3m A \u0111\u1ebfn \u0111\u1ecba \u0111i\u1ec3m B. Sau \u0111o n\u1eeda gi\u1edd m\u1ed9t xe m\u00e1y \u0111i v\u1edbi v\u1eadn t\u1ed1c 24 km\/gi\u1edd c\u00f9ng xu\u1ea5t ph\u00e1t t\u1eeb A \u0111\u1ec3 \u0111i \u0111\u1ebfn B. H\u1ecfi tr\u00ean \u0111\u1eddng AB v\u00e0o l\u00fac m\u1ea5y gi\u1edd xe m\u00e1y \u1edf \u0111\u00fang \u0111i\u1ec3m ch\u00ednh gi\u1eefa kho\u1ea3ng c\u00e1ch gi\u1eefa xe \u0111\u1ea1p v\u00e0 \u00f4 t\u00f4? B\u00e0i 22: M\u1ed9t con ch\u00f3 \u0111u\u1ed5i m\u1ed9t con th\u1ecf \u1edf c\u00e1ch xa n\u00f3 17 b\u1edbc c\u1ee7a ch\u00f3. Con th\u1ecf \u1edf c\u00e1ch hang n\u00f3 80 b\u1edbc c\u1ee7a th\u1ecf. Khi th\u1ecf ch\u1ea1y \u0111\u1ee3c 3 b\u1edbc th\u00ec ch\u00f3 ch\u00e1y \u0111\u1ee3c 1 b\u1edbc. M\u1ed9t b\u1edbc c\u1ee7a ch\u00f3 b\u1eb1ng 8 b\u1edbc c\u1ea3u th\u1ecf. H\u1ecfi ch\u00f3 c\u00f3 b\u1eaft \u0111\u1ee3c th\u1ecf kh\u00f4ng? B\u00e0i 23: M\u1ed9t con chu\u1ed9t ki\u1ebfm \u0103n c\u00e1ch hang 30m. B\u1ed7ng tr\u00f4ng th\u1ea5y m\u1ed9t con m\u00e8o c\u00e1ch n\u00f3 20m tr\u00ean c\u00f9ng \u0111\u1eddng ch\u1ea1y v\u1ec1 hang. Chu\u1ed9t v\u1ed9i ch\u1ea1y ch\u1ed1n m\u1ed7i gi\u00e2y 5m, m\u00e8o v\u1ed9i \u0111u\u1ed5i theo m\u1ed7i ph\u00fat 480m. H\u1ecfi m\u00e8o c\u00f3 v\u1ed3 \u0111\u1ee3c chu\u1ed9t kh\u00f4ng? B\u00e0i 24: M\u1ed9t chi\u1ebfc t\u00e0u thu\u1ef7 c\u00f3 chi\u1ec1u d\u00e0i 15m ch\u1ea1y ng\u1ee3c d\u00f2ng. C\u00f9ng l\u00fac \u0111\u00f3 m\u1ed9t chi\u1ebfc t\u00e0u c\u00f3 chi\u1ec1u d\u00e0i 20m ch\u1ea1y xu\u00f4i d\u00f2ng v\u1edbi v\u1eadn t\u1ed1c g\u1ea5p r\u1ee1i v\u1eadn t\u1ed1c c\u1ee7a t\u00e0u ng\u1ee3c d\u00f2ng. Sau 4 ph\u00fat th\u00ec 2 chi\u1ebfc t\u00e0u v\u1ee3t qua nhau. T\u00ednh v\u1eadn t\u1ed1c c\u1ee7a m\u1ed7i t\u00e0u, bi\u1ebft r\u1eb1ng kho\u1ea3ng c\u00e1ch gi\u1eefa hai t\u00e0u l\u00e0 165m. B\u00e0i 25: M\u1ed9t ca n\u00f4 ch\u1ea1y tr\u00ean kh\u00fac s\u00f4ng t\u1eeb b\u1ebfn A \u0111\u1ebfn b\u1ebfn B khi xu\u00f4i d\u00f2ng h\u1ebft 6 gi\u1edd, khi ng\u1ee3c d\u00f2ng h\u1ebft 8 gi\u1edd. H\u00e3y t\u00ednh kho\u1ea3ng c\u00e1ch AB, bi\u1ebft r\u1eb1ng n\u1edbc ch\u1ea3y v\u1edbi v\u1eadn t\u1ed1c 5 km\/gi\u1edd. B\u00e0i 26: M\u1ed9t xe l\u1eeda d\u00e0i 150m ch\u1ea1y v\u1edbi v\u1eadn t\u1ed1c 58,2 km\/gi\u1edd. Xe l\u1eeda g\u1eb7p m\u1ed9t ng\u1eddi \u0111i b\u1ed9 c\u00f9ng chi\u1ec1u tr\u00ean con \u0111\u1eddng song song v\u1edbi \u0111\u1eddng s\u1eaft. V\u1eadn t\u1ed1c c\u1ee7a ng\u1eddi \u0111i b\u1ed9 l\u00e0 4,2 km\/gi\u1edd. T\u00ednh th\u1eddi gian t\u1eeb l\u00fac xe l\u1eeda g\u1eb7p ng\u1eddi \u0111i b\u1ed9 \u0111\u1ebfn khi xe l\u1eeda v\u1ee3t qua kh\u1ecfi ng\u1eddi \u0111\u00f3. B\u00e0i 27: M\u1ed9t xe l\u1eeda ch\u1ea1y v\u1edbi v\u1eadn t\u1ed1c 32,4 km\/gi\u1edd. M\u1ed9t xe Honda ch\u1ea1y c\u00f9ng chi\u1ec1u tr\u00ean con \u0111\u1eddng song song v\u1edbi \u0111\u1eddng s\u1eaft. T\u1eeb khi xe Honda \u0111u\u1ed5i k\u1ecbp toa c\u1ed1i \u0111\u1ebfn khi xe Honda v\u1ee3t kh\u1ecfi xe l\u1eeda m\u1ea5t 25 gi\u00e2y. T\u00ednh chi\u1ec1u d\u00e0i xe l\u1eeda, bi\u1ebft v\u1eadn t\u1ed1c xe Honda b\u1eb1ng 54 km\/gi\u1edd. B\u00e0i 28: M\u1ed9t \u00f4 t\u00f4 g\u1eb7p m\u1ed9t xe l\u1eeda ch\u1ea1y ng\u1ee3c chi\u1ec1u tr\u00ean 2 \u0111o\u1ea1n \u0111\u1eddng song song. M\u1ed9t h\u00e0nh kh\u00e1ch tr\u00ean \u00f4 t\u00f4 th\u1ea5y t\u1eeb l\u00fac toa \u0111\u1ea7u v\u00e0 toa cu\u1ed1i c\u1ee7a xe l\u1eeda qua kh\u1ecfi m\u00ecnh m\u1ea5t 7 gi\u00e2y. T\u00ednh v\u1eadn t\u1ed1c theo gi\u1edd c\u1ee7a xe l\u1eeda, bi\u1ebft r\u1eb1ng xe l\u1eeda c\u00f3 chi\u1ec1u d\u00e0i 196m, v\u1eadn t\u1ed1c \u00f4 t\u00f4 l\u00e0 960 m\/ph\u00fat. B\u00e0i 29: M\u1ed9t xe l\u1eeda v\u1ee3t qua c\u00e1i c\u1ea7u d\u00e0i 450m m\u1ea5t 45 gi\u00e2y, v\u1ee3t qua m\u1ed9t c\u1ed9t \u0111i\u1ec7n m\u1ea5t 15 gi\u00e2y v\u00e0 v\u1ee3t qua m\u1ed9t ng\u1eddi \u0111i xe \u0111\u1ea1p c\u00f9ng chi\u1ec1u m\u1ea5t 25 gi\u00e2y. T\u00ecm v\u1eadn t\u1ed1c c\u1ee7a ng\u1eddi \u0111i xe \u0111\u1ea1p. 51","Chuy\u00ean \u0111\u1ec1 b\u1ed3i d\u01b0\u1ee1ng HS l\u1edbp 5. CHUY\u00caN \u0110\u1ec0 16 TR\u00d2 CH\u01a0I B\u00e0i 1: V\u0129nh v\u00e0 Ph\u00fac ch\u01a1i c\u00e1c tr\u00f2 ch\u01a1i l\u1ea5y c\u00e1c \u0111\u1ed3ng xu t\u1eeb m\u1ed9t ch\u1ed3ng c\u00f3 1999 \u0111\u1ed3ng xu. V\u0129nh v\u00e0 Ph\u00fac l\u1ea7n l\u1ee3t ch\u01a1i, V\u0129nh \u0111i tr\u1edbc. Trong m\u1ed7i l\u1ee3t, V\u0129nh v\u00e0 Ph\u00fac c\u00f3 th\u1ec3 l\u1ea5y m\u1ed9t, ho\u1eb7c hai, ho\u1eb7c ba \u0111\u1ed3ng xu. Ai l\u1ea5y \u0111\u1ed3ng xu cu\u1ed1i c\u00f9ng l\u00e0 ng\u1eddi \u1ea5y thua cu\u1ed9c. H\u1ecfi V\u0129nh n\u00ean l\u1ea5y bao nhi\u00eau \u0111\u1ed3ng xu trong l\u1ee3t \u0111i \u0111\u1ea7u ti\u00ean \u0111\u1ec3 ch\u1eafc ch\u1eafn l\u00e0 ng\u1eddi th\u1eafng cu\u1ed9c? B\u00e0i 2: Tr\u00ean m\u1eb7t b\u00e0n c\u00f3 18 que di\u00eam. Hai ng\u1eddi tham gia cu\u1ed9c ch\u01a1i. M\u1ed7i ng\u1eddi l\u1ea7n l\u1ee3t \u0111\u1ebfn phi\u00ean m\u00ecnh l\u1ea5y ra m\u1ed9t s\u1ed1 que di\u00eam. M\u1ed7i l\u1ea7n, m\u1ed7i ng\u1eddi l\u1ea5y ra kh\u00f4ng qu\u00e1 4 que. Ng\u1eddi n\u00e0o l\u1ea5y \u0111\u1ee3c s\u1ed1 que cu\u1ed1i c\u00f9ng th\u00ec ng\u1eddi \u0111\u00f3 th\u1eafng. N\u1ebfu b\u1ea1n b\u1ed1c tr\u1edbc, b\u1ea1n c\u00f3 ch\u1eafc ch\u1eafn th\u1eafng \u0111\u1ee3c kh\u00f4ng ? B\u00e0i 3: Tr\u00ean m\u1eb7t b\u00e0n c\u00f3 50 chi\u1ebfc nh\u00e3n v\u1edf. To\u00e1n v\u00e0 Th\u01a1 ch\u01a1i m\u1ed9t tr\u00f2 ch\u01a1i nh sau: Hai b\u1ea1n l\u1ea7n l\u1ee3t l\u1ea5y nh\u00e3n v\u1edf tr\u00ean b\u00e0n, m\u1ed7i l\u1ee3t ch\u1ec9 \u0111\u1ee3c l\u1ea5y 1 ho\u1eb7c 2 nh\u00e3n v\u1edf, \u0111\u1ebfn l\u1ee3t ai m\u00e0 tr\u00ean b\u00e0n kh\u00f4ng c\u00f2n nh\u00e3n v\u1edf \u0111\u1ec3 l\u1ea5y th\u00ec ng\u1eddi \u0111\u00f3 thua. Bi\u1ebft r\u1eb1ng l\u1ee3t \u0111\u1ea7u ti\u00ean To\u00e1n l\u1ea5y 1 nh\u00e3n v\u1edf. H\u00e3y cho bi\u1ebft To\u00e1n c\u00f3 th\u1ec3 ch\u1eafc ch\u1eafn th\u1eafng Th\u01a1 \u0111\u1ee3c kh\u00f4ng ? B\u00e0i 4: Trong m\u1ed9t c\u00e1i h\u1ed9p c\u00f3 10 vi\u00ean bi \u0111\u1ecf v\u00e0 5 vi\u00ean bi xanh. T\u00f9ng b\u1ed1c m\u1ed7i l\u1ea7n 2 vi\u00ean bi b\u1ecf ra ngo\u00e0i, sau \u0111\u00f3 l\u1ea1i b\u1ecf v\u00e0o trong h\u1ed9p m\u1ed9t vi\u00ean bi n\u1ebfu 2 vi\u00ean bi \u0111\u1ee3c l\u1ea5y ra c\u00f3 m\u00e0u gi\u1ed1ng nhau, b\u1ecf v\u00e0o m\u1ed9t vi\u00ean bi xanh n\u1ebfu 2 vi\u00ean bi l\u1ea5y ra c\u00f3 m\u00e0u kh\u00e1c nhau. H\u1ecfi sau 14 T\u00f9ng l\u1ea5y ra v\u00e0 b\u1ecf v\u00e0o nh th\u1ebf Th\u00ec trong h\u1ed9p c\u00f2n bao nhi\u00eau vi\u00ean bi, m\u00e0u s\u1eafc c\u1ee7a ch\u00fang nh th\u1ebf n\u00e0o? H\u1ebft 52"]