\n- Tr\u01b0\u1eddng h\u1ee3p 1: N\u1ebfu l\u00e0 s\u1ed1 c\u00f3 2 ch\u1eef s\u1ed1 > 10 th\u00ec ch\u00fang ta s\u1ebd \u0111\u01b0\u1ee3c con s\u1ed1 b\u1ea1ch th\u1ee7 \u0111\u1ec1 c\u1ee7a ng\u00e0y h\u00f4m sau. \u0110\u1ec3 t\u00ecm ra \u0111\u01b0\u1ee3c con s\u1ed1 3 c\u00e0ng b\u1ea1ch th\u1ee7 anh em h\u00e3y tham kh\u1ea3o xem gi\u1ea3i 7 c\u00f3 con s\u1ed1 n\u00e0o l\u00e0 con s\u1ed1 k\u00e9p b\u1eb1ng hay kh\u00f4ng. N\u1ebfu c\u00f3 th\u00ec \u0111em gh\u00e9p t\u1ed5ng s\u1ed1 \u0111\u1ec1 v\u1eeba t\u00ecm \u0111\u01b0\u1ee3c v\u1edbi con s\u1ed1 k\u00e9p b\u1eb1ng, con s\u1ed1 k\u00e9p b\u1eb1ng ch\u00ednh l\u00e0 s\u1ed1 ch\u1ea1m \u0111\u1ea7u ti\u00ean c\u1ee7a con s\u1ed1 3 c\u00e0ng.<\/li>\n\n\n\n
- Tr\u01b0\u1eddng h\u1ee3p 2: N\u1ebfu t\u1ed5ng \u0111\u1ec1 v\u1eeba t\u00ecm \u0111\u01b0\u1ee3c <10, ta gh\u00e9p l\u1ea7n l\u01b0\u1ee3t c\u00e1c con s\u1ed1 n\u00e0y l\u1ea1i v\u1edbi nhau \u0111\u1ec3 t\u1ea1o th\u00e0nh d\u00e0n \u0111\u1ec1 3 c\u00e0ng. \u1ede tr\u01b0\u1eddng h\u1ee3p n\u00e0y con s\u1ed1 ch\u00fang ta t\u00ecm \u0111\u01b0\u1ee3c l\u1edbn h\u01a1n so v\u1edbi tr\u01b0\u1eddng h\u1ee3p 1. N\u00ean khi v\u00e0o ti\u1ec1n anh em h\u00e3y c\u00e2n nh\u1eafc l\u1ea1i c\u1ea9n th\u1eadn h\u01a1n nh\u00e9.<\/li>\n<\/ul>\n\n\n\n
V\u00ed d\u1ee5: <\/p>\n\n\n\n
\n- T\u1ed5ng \u0111\u1ec1 l\u00e0 42 ta c\u00f3 4+2 = 6. Gh\u00e9p con s\u1ed1 n\u00e0y l\u1ea7n l\u01b0\u1ee3t v\u1edbi c\u00e1c gi\u1ea3i b\u1ea3y c\u1ee7a b\u1ea3ng k\u1ebft qu\u1ea3 x\u1ed5 s\u1ed1 \u0111\u1ec3 \u0111\u01b0\u1ee3c 1 d\u00e0n c\u00e1c con s\u1ed1 3 c\u00e0ng.<\/li>\n\n\n\n
- T\u1ed5ng \u0111\u1ec1 l\u00e0 96 c\u00f3 t\u1ed5ng 9+6 = 15. T\u00ecm ki\u1ebfm con l\u00f4 k\u00e9p n\u1eb1m \u1edf gi\u1ea3i b\u1ea3y gh\u00e9p l\u1ea1i v\u1edbi t\u1ed5ng \u0111\u1ec1 n\u00e0y ta \u0111\u01b0\u1ee3c con s\u1ed1 3 c\u00e0ng b\u1ea1ch th\u1ee7 h\u00f4m nay.<\/li>\n<\/ul>\n\n\n\n