3袋大米和4袋面粉共重640千克,5袋大米和2袋面粉共重600千克,每袋大米和每袋面粉各重多少千克?
问题描述:
3袋大米和4袋面粉共重640千克,5袋大米和2袋面粉共重600千克,每袋大米和每袋面粉各重多少千克?
答
(600×4-640×2)÷(5×4-3×2),
=(2400-1280)÷14,
=1120÷14,
=80(千克),
(640-80×3)÷4,
=(640-240)÷4,
=400÷4,
=100(千克),
答:每袋大米80千克,每袋面粉100千克.