奥数题库 六年级 浓度问题 有若干千克4%的盐水,蒸发了一些水分后变成了10%的盐水,再加入300克4%的盐水混 小学奥数题 浓度问题
\u516d\u5e74\u7ea7\u5965\u6570\u9898\u548c\u7b54\u6848\uff0850\u9898\uff091. \u6709 28\u4f4d\u5c0f\u670b\u53cb\u6392\u6210\u4e00\u884c .\u4ece\u5de6\u8fb9\u5f00\u59cb\u6570\u7b2c 10\u4f4d\u662f\u7231\u534e\uff0c\u4ece\u53f3\u8fb9\u5f00\u59cb\u6570\u4ed6\u662f\u7b2c\u51e0\u4f4d\uff1f
2. \u7ebd\u7ea6\u65f6\u95f4\u662f\u9999\u6e2f\u65f6\u95f4\u51cf 13\u5c0f\u65f6 .\u4f60\u4e0e\u4e00\u4f4d\u5728\u7ebd\u7ea6\u7684\u670b\u53cb\u7ea6\u5b9a\uff0c\u7ebd\u7ea6\u65f6\u95f4 4\u6708 1\u65e5\u665a\u4e0a 8\u65f6\u4e0e\u4ed6\u901a\u7535\u8bdd\uff0c\u90a3\u4e48\u5728\u9999\u6e2f\u4f60\u5e94\u51e0\u6708\u51e0\u65e5\u51e0\u65f6\u7ed9\u4ed6\u6253\u7535\u8bdd\uff1f
3. \u540d\u5de5\u4eba 5\u5c0f\u65f6\u52a0\u5de5\u96f6\u4ef6 90\u4ef6\uff0c\u8981\u5728 10\u5c0f\u65f6\u5b8c\u6210 540\u4e2a\u96f6\u4ef6\u7684\u52a0\u5de5\uff0c\u9700\u8981\u5de5\u4eba\u591a\u5c11\u4eba\uff1f
4. \u5927\u4e8e 100\u7684\u6574\u6570\u4e2d\uff0c\u88ab 13\u9664\u540e\u5546\u4e0e\u4f59\u6570\u76f8\u540c\u7684\u6570\u6709\u591a\u5c11\u4e2a\uff1f
5. \u56db\u4e2a\u623f\u95f4\uff0c\u6bcf\u4e2a\u623f\u95f4\u91cc\u4e0d\u5c11\u4e8e 2\u4eba\uff0c\u4efb\u4f55\u4e09\u4e2a\u623f\u95f4\u91cc\u7684\u4eba\u6570\u4e0d\u5c11 8\u4eba\uff0c\u8fd9\u56db\u4e2a\u623f\u95f4\u81f3\u5c11\u6709\u591a\u5c11\u4eba\uff1f
6. \u5728 1998\u7684\u7ea6\u6570\uff08\u6216\u56e0\u6570\uff09\u4e2d\u6709\u4e24\u4f4d\u6570\uff0c\u5176\u4e2d\u6700\u5927\u7684\u662f\u54ea\u4e2a\u6570\uff1f
7. \u82f1\u6587\u6d4b\u9a8c\uff0c\u5c0f\u660e\u524d\u4e09\u6b21\u5e73\u5747\u5206\u662f 88\u5206\uff0c\u8981\u60f3\u5e73\u5747\u5206\u8fbe\u5230 90\u5206\uff0c\u4ed6\u7b2c\u56db\u6b21\u6700\u5c11\u8981\u5f97\u51e0\u5206\uff1f
8. \u4e00\u4e2a\u6708\u6700\u591a\u6709 5\u4e2a\u661f\u671f\u65e5\uff0c\u5728\u4e00\u5e74\u7684 12\u4e2a\u6708\u4e2d\uff0c\u6709 5\u4e2a\u661f\u671f\u65e5\u7684\u6708\u4efd\u6700\u591a\u6709\u51e0\u4e2a\u6708\uff1f
9. \u5c06 0\uff0c 1\uff0c 2\uff0c 3\uff0c 4\uff0c 5\uff0c 6\uff0c 7\uff0c 8\uff0c 9\u8fd9\u5341\u4e2a\u6570\u5b57\u4e2d\uff0c\u9009\u51fa\u516d\u4e2a\u586b\u5728\u4e0b\u9762\u65b9\u6846\u4e2d\uff0c\u4f7f\u7b97\u5f0f\u6210\u7acb\uff0c\u4e00\u4e2a\u65b9\u6846\u586b\u4e00\u4e2a\u6570\u5b57\uff0c\u5404\u4e2a\u65b9\u6846\u6570\u5b57\u4e0d\u76f8\u540c .
\u25a1 +\u25a1\u25a1 =\u25a1\u25a1\u25a1
\u95ee\u7b97\u5f0f\u4e2d\u7684\u4e09\u4f4d\u6570\u6700\u5927\u662f\u4ec0\u4e48\u6570\uff1f
10. \u6709\u4e00\u4e2a\u53f7\u7801\u662f\u516d\u4f4d\u6570\uff0c\u524d\u56db\u4f4d\u662f 2857\uff0c\u540e\u4e24\u4f4d\u8bb0\u4e0d\u6e05\uff0c\u5373
2857\u25a1\u25a1
\u4f46\u662f\u6211\u8bb0\u5f97\uff0c\u5b83\u80fd\u88ab 11\u548c 13\u6574\u9664\uff0c\u8bf7\u4f60\u7b97\u51fa\u540e\u4e24\u4f4d\u6570 .
11. \u67d0\u5b66\u6821\u6709\u5b66\u751f 518\u4eba\uff0c\u5982\u679c\u7537\u751f\u589e\u52a0 4\uff05\uff0c\u5973\u751f\u51cf\u5c11 3\u4eba\uff0c\u603b\u4eba\u6570\u5c31\u589e\u52a0 8\u4eba\uff0c\u90a3\u4e48\u539f\u6765\u7537\u751f\u6bd4\u5973\u751f\u591a\u51e0\u4eba\uff1f
12. \u9648\u654f\u8981\u8d2d\u7269\u4e09\u6b21\uff0c\u4e3a\u4e86\u4f7f\u6bcf\u6b21\u90fd\u4e0d\u4ea7\u751f 10\u5143\u4ee5\u4e0b\u7684\u627e\u8d4e\uff0c 5\u5143\u3001 2\u5143\u3001 1\u5143\u7684\u786c\u5e01\u6700\u5c11\u603b\u5171\u8981\u5e26\u51e0\u4e2a\uff1f
\uff08\u786c\u5e01\u53ea\u6709 5\u5143\u3001 2\u5143\u3001 1\u5143\u4e09\u79cd .\uff09
13. \u53f3\u56fe\u662f\u4e09\u4e2a\u534a\u5706\u6784\u6210\u7684\u56fe\u5f62\uff0c\u5176\u4e2d\u5c0f\u5706\u76f4\u5f84\u4e3a 8\uff0c\u4e2d\u5706\u76f4\u5f84\u4e3a 12\uff0c
14.\u5e7c\u513f\u56ed\u7684\u8001\u5e08\u628a\u4e00\u4e9b\u753b\u7247\u5206\u7ed9 A\uff0c B\uff0c C\u4e09\u4e2a\u73ed\uff0c\u6bcf\u4eba\u90fd\u80fd\u5206\u5230 6\u5f20 .\u5982\u679c\u53ea\u5206\u7ed9 B\u73ed\uff0c\u6bcf\u4eba\u80fd\u5f97 15\u5f20\uff0c\u5982\u679c\u53ea\u5206\u7ed9 C\u73ed\uff0c\u6bcf\u4eba\u80fd\u5f97 14\u5f20\uff0c\u95ee\u53ea\u5206\u7ed9 A\u73ed\uff0c\u6bcf\u4eba\u80fd\u5f97\u51e0\u5f20\uff1f
15. \u4e24\u4eba\u505a\u4e00\u79cd\u6e38\u620f\uff1a\u8f6e\u6d41\u62a5\u6570\uff0c\u62a5\u51fa\u7684\u6570\u53ea\u80fd\u662f 1\uff0c 2\uff0c 3\uff0c 4\uff0c 5\uff0c 6\uff0c 7\uff0c 8.\u628a\u4e24\u4eba\u62a5\u51fa\u7684\u6570\u8fde\u52a0\u8d77\u6765\uff0c\u8c01\u62a5\u6570\u540e\uff0c\u52a0\u8d77\u6765\u7684\u6570\u662f 123\uff0c\u8c01\u5c31\u83b7\u80dc\uff0c\u8ba9\u4f60\u5148\u62a5\uff0c\u5c31\u4e00\u5b9a\u4f1a\u8d62\uff0c\u90a3\u4e48\u4f60\u7b2c\u4e00\u4e2a\u6570\u62a5\u51e0\uff1f
16.\u4e00\u672c\u5c0f\u8bf4\u7684\u9875\u7801\uff0c\u5728\u5370\u5237\u65f6\u5fc5\u987b\u75281989\u4e2a\u94c5\u5b57\uff0c\u5728\u8fd9\u4e00\u672c\u4e66\u7684\u9875\u7801\u4e2d\u6570\u5b571\u51fa\u73b0\u591a\u5c11\u6b21\uff1f
17.\u628a23\u4e2a\u6570\uff1a3\uff0c33\uff0c333\uff0c\u2026\uff0c33\u20263\uff0823\u4e2a3\uff09\u76f8\u52a0\uff0c\u5219\u6240\u5f97\u7684\u548c\u7684\u672b\u56db\u4f4d\u6570\u662f\u591a\u5c11\uff1f
18.\u5c061\u30011\u30012\u30012\u30013\u30013\u30014\u30014\u8fd9\u516b\u4e2a\u6570\u5b57\u6392\u6210\u4e00\u4e2a\u516b\u4f4d\u6570\uff0c\u4f7f\u5f97\u4e24\u4e2a1\u4e4b\u95f4\u6709\u4e00\u4e2a\u6570\u5b57\uff0c\u4e24\u4e2a2\u4e4b\u95f4\u6709\u4e8c\u4e2a\u6570\u5b57\uff0c\u4e24\u4e2a3\u4e4b\u95f4\u6709\u4e09\u4e2a\u6570\u5b57\uff0c\u4e24\u4e2a4\u4e4b\u95f4\u6709\u56db\u4e2a\u6570\u5b57\uff0c\u90a3\u4e48\u8fd9\u6837\u7684\u516b\u4f4d\u6570\u4e2d\u6700\u5c0f\u7684\u662f\uff1f
19.\u4ece 1\uff0c 2\uff0c 3\uff0c\u2026\uff0c2004\uff0c 2005\u8fd9\u4e9b\u81ea\u7136\u6570\u4e2d\uff0c\u6700\u591a\u53ef\u4ee5\u53d6\u51e0\u4e2a\u6570\uff0c\u624d\u80fd\u4f7f\u5176\u4e2d\u6bcf\u4e24\u4e2a\u6570\u7684\u5dee\u4e0d\u7b49\u4e8e4\uff1f
20.\u6709\u4e00\u4e2a\u7535\u8bdd\u53f7\u7801\u662f\u516d\u4f4d\u6570\uff0c\u5176\u4e2d\u5de6\u8fb9\u4e09\u4e2a\u6570\u5b57\u76f8\u540c\uff0c\u53f3\u8fb9\u4e09\u4e2a\u6570\u5b57\u662f\u4e09\u4e2a\u8fde\u7eed\u7684\u81ea\u7136\u6570\uff0c\u516d\u4e2a\u6570\u5b57\u4e4b\u548c\u6070\u597d\u7b49\u4e8e\u672b\u5c3e\u7684\u4e24\u4f4d\u6570\uff0c\u8fd9\u4e2a\u7535\u8bdd\u53f7\u7801\u662f\u591a\u5c11\uff1f
21.\u82e5a\u4e3a\u81ea\u7136\u6570\uff0c\u8bc1\u660e10\u2502\uff08a2005\uff0da1949\uff09\uff0e
22.\u7ed9\u51fa12\u4e2a\u5f7c\u6b64\u4e0d\u540c\u7684\u4e24\u4f4d\u6570\uff0c\u8bc1\u660e\uff1a\u7531\u5b83\u4eec\u4e2d\u4e00\u5b9a\u53ef\u4ee5\u9009\u51fa\u4e24\u4e2a\u6570\uff0c\u5b83\u4eec\u7684\u5dee\u662f\u4e24\u4e2a\u76f8\u540c\u6570\u5b57\u7ec4\u6210\u7684\u4e24\u4f4d\u6570\uff0e
23.\u6c42\u88ab3\u9664\u4f592\uff0c\u88ab5\u9664\u4f593\uff0c\u88ab7\u9664\u4f595\u7684\u6700\u5c0f\u4e09\u4f4d\u6570\uff0e
24.\u8bbe2n\uff0b1\u662f\u8d28\u6570\uff0c\u8bc1\u660e\uff1a12\uff0c22\uff0c\u2026\uff0cn2\u88ab2n\uff0b1\u9664\u6240\u5f97\u7684\u4f59\u6570\u5404\u4e0d\u76f8\u540c\uff0e
25.\u8bd5\u8bc1\u4e0d\u5c0f\u4e8e5\u7684\u8d28\u6570\u7684\u5e73\u65b9\u4e0e1\u7684\u5dee\u5fc5\u80fd\u88ab24\u6574\u9664\uff0e
26. \u6709\u7532\u4e59\u4e24\u79cd\u7cd6\u6c34\uff0c\u7532\u542b\u7cd6270\u514b\uff0c\u542b\u6c3430\u514b\uff0c\u4e59\u542b\u7cd6400\u514b\uff0c\u542b\u6c34100\u514b\uff0c\u73b0\u8981\u5f97\u5230\u6d53\u5ea6\u662f82.5%\u7684\u7cd6\u6c34100\u514b\uff0c\u95ee\u6bcf\u79cd\u5e94\u53d6\u591a\u5c11\u514b\uff1f
27. \u4e00\u4e2a\u5bb9\u5668\u91cc\u88c5\u670910\u5347\u7eaf\u9152\u7cbe,\u5012\u51fa1\u5347\u540e,\u7528\u6c34\u52a0\u6ee1,\u518d\u5012\u51fa1\u5347,\u7528\u6c34\u52a0\u6ee1,\u518d\u5012\u51fa1\u5347,\u7528\u6c34\u52a0\u6ee1,\u8fd9\u65f6\u5bb9\u5668\u5185\u7684\u9152\u7cbe\u6eb6\u6db2\u7684\u6d53\u5ea6\u662f?
28. \u6709\u82e5\u5e72\u5343\u514b4%\u7684\u76d0\u6c34,\u84b8\u53d1\u4e86\u4e00\u4e9b\u6c34\u5206\u540e\u53d8\u6210\u4e8610%\u7684\u76d0\u6c34,\u5728\u52a0300\u514b4%\u7684\u76d0\u6c34,\u6df7\u5408\u540e\u53d8\u62106.4%\u7684\u76d0\u6c34,\u95ee\u6700\u521d\u7684\u76d0\u6c34\u662f\u591a\u5c11\u5343\u514b?
29.\u5df2\u77e5\u76d0\u6c34\u82e5\u5e72\u514b\uff0c\u7b2c\u4e00\u6b21\u52a0\u5165\u4e00\u5b9a\u91cf\u7684\u6c34\u540e\uff0c\u76d0\u6c34\u6d53\u5ea6\u53d8\u4e3a3\uff05\uff0c\u7b2c\u4e8c\u6b21\u52a0\u5165\u540c\u6837\u591a\u7684\u6c34\u540e\uff0c\u76d0\u6c34\u6d53\u5ea6\u53d8\u4e3a2\uff05\u3002\u6c42\u7b2c\u4e09\u6b21\u52a0\u5165\u540c\u6837\u591a\u7684\u6c34\u540e\u76d0\u6c34\u7684\u6d53\u5ea6\u3002
30.\u6709A\u3001B\u3001C\u4e09\u79cd\u76d0\u6c34\uff0c\u6309A\u4e0eB\u7684\u6570\u91cf\u4e4b\u6bd4\u4e3a2\uff1a1\u6df7\u5408\uff0c\u5f97\u5230\u6d53\u5ea6\u4e3a13\uff05\u7684\u76d0\u6c34\uff1b\u6309A\u4e0eB\u7684\u6570\u91cf\u4e4b\u6bd4\u4e3a1\uff1a2\u6df7\u5408\uff0c\u5f97\u5230\u6d53\u5ea6\u4e3a14\uff05\u7684\u76d0\u6c34\uff1b\u6309A\u3001B\u3001C\u7684\u6570\u91cf\u4e4b\u6bd4\u4e3a1\uff1a1\uff1a3\u6df7\u5408\uff0c\u5f97\u5230\u6d53\u5ea6\u4e3a10.2\uff05\u7684\u76d0\u6c34\uff0c\u95ee\u76d0\u6c34C\u7684\u6d53\u5ea6\u662f\u591a\u5c11\uff1f
[ \u7b54\u6848 ]
1. \u4ece\u53f3\u8fb9\u5f00\u59cb\u6570\uff0c\u4ed6\u662f\u7b2c 19\u4f4d .
2. 4 \u67082 \u65e5\u4e0a\u53489 \u65f6.
3.9\u540d\u5de5\u4eba .
4.\u6709 5\u4e2a .
13\u00d7 7+7=98\uff1c 100\uff0c\u5546\u6570\u4ece 8\u5f00\u59cb .\u4f46\u4f59\u6570\u5c0f\u4e8e 13\uff0c\u6700\u5927\u662f 12\uff0c\u6709 13\u00d7 8\uff0b 8\uff1d 112\uff0c 13\u00d7 9\uff0b 9\uff1d 126\uff0c 13\u00d7 10\uff0b 10=140\uff0c 13\u00d7 11\uff0b 11=154\uff0c 13\u00d7 12\uff0b 12\uff1d 168\uff0c\u5171 5\u4e2a\u6570 .
5.\u81f3\u5c11\u6709 11\u4eba .
\u4eba\u6570\u6700\u591a\u7684\u623f\u95f4\u81f3\u5c11\u6709 3\u4eba\uff0c\u5176\u4f59\u4e09\u4e2a\u623f\u95f4\u81f3\u5c11\u6709 8\u4eba\uff0c\u603b\u5171\u81f3\u5c11\u6709 11\u4eba .
6.\u6700\u5927\u7684\u4e24\u4f4d\u7ea6\u6570\u662f 74.
1998\uff1d 2\u00d7 3\u00d7 3\u00d7 3\u00d7 37
7.\u7b2c\u56db\u6b21\u6700\u5c11\u8981\u5f97 96\u5206 .
88\uff0b\uff08 90- 88\uff09\u00d7 4=96\uff08\u5206\uff09
8.\u6700\u591a\u6709 5\u4e2a\u6708\u6709 5\u4e2a\u661f\u671f\u65e5 .
1\u6708 1\u65e5\u662f\u661f\u671f\u65e5\uff0c\u5168\u5e74\u5c31\u6709 53\u4e2a\u661f\u671f\u65e5 .\u6bcf\u6708\u81f3\u5c11\u6709 4\u4e2a\u661f\u671f\u65e5\uff0c 53-4\u00d7 12=5\uff0c\u591a\u51fa 5\u4e2a\u661f\u671f\u65e5\uff0c\u5728 5\u4e2a\u6708\u4e2d .
9.105.
\u548c\u7684\u524d\u4e24\u4f4d\u662f 1\u548c 0\uff0c\u4e24\u4f4d\u6570\u7684\u5341\u4f4d\u662f 9.\u56e0\u6b64\u52a0\u6570\u7684\u4e2a\u4f4d\u6700\u5927\u662f 7\u548c 8.
10.\u540e\u4e24\u4f4d\u6570\u662f 14.
285700\u00f7\uff08 11\u00d7 13\uff09 =1997\u4f59 129
\u4f59\u6570 129\u518d\u52a0 14\u5c31\u80fd\u88ab 143\u6574\u9664 .
11.\u7537\u751f\u6bd4\u5973\u751f\u591a 32\u4eba .
\u7537\u751f 4\uff05\u662f 3\uff0b 8=11\uff08\u4eba\uff09\uff0c\u7537\u751f\u6709 11\u00f7 4\uff05 =275\uff08\u4eba\uff09\uff0c\u5973\u751f\u6709 518-275=243\uff08\u4eba\uff09\uff0c 275-243=32\uff08\u4eba\uff09 .
12.\u6700\u5c11 5\u5143\u3001 2\u5143\u3001 1\u5143\u7684\u786c\u5e01\u5171 11\u4e2a .
\u8d2d\u7269 3\u6b21\uff0c\u5fc5\u987b\u5907\u6709 3\u4e2a 5\u5143\u3001 3\u4e2a 2\u5143\u3001 3\u4e2a 1\u5143 .\u4e3a\u4e86\u5e94\u4ed8 3\u6b21\u90fd\u662f 4\u5143\uff0c\u81f3\u5c11\u8fd8\u8981 2\u4e2a\u786c\u5e01\uff0c\u4f8b\u5982 2\u5143\u548c 1\u5143\u5404\u4e00\u4e2a\uff0c\u56e0\u6b64\uff0c\u603b\u6570 11\u4e2a\u662f\u4e0d\u80fd\u5c11\u7684 .\u51c6\u5907 5\u5143 3\u4e2a\uff0c 2\u5143 5\u4e2a\uff0c 1\u5143 3\u4e2a\uff0c\u6216\u8005 5\u5143 3\u4e2a\uff0c 2\u5143 4\u4e2a\uff0c 1\u5143 4\u4e2a\u5c31\u80fd\u4e09\u6b21\u652f\u4ed8 1\u5143\u81f3 9\u5143\u4efb\u4f55\u94b1\u6570 .
14.A\u73ed\u6bcf\u4eba\u80fd\u5f97 35\u5f20 .
\u8bbe\u4e09\u73ed\u603b\u4eba\u6570\u662f 1\uff0c\u5219 B\u73ed\u4eba\u6570\u662f 6/15\uff0c C\u73ed\u4eba\u6570\u662f 6/14\uff0c\u56e0\u6b64 A\u73ed\u4eba\u6570\u662f\uff1a
15.\u7b2c\u4e00\u4e2a\u6570\u62a5 6.
\u5bf9\u65b9\u81f3\u5c11\u8981\u62a5\u6570 1\uff0c\u81f3\u591a\u62a5\u6570 8\uff0c\u4e0d\u8bba\u5bf9\u65b9\u62a5\u4ec0\u4e48\u6570\uff0c\u4f60\u603b\u662f\u53ef\u4ee5\u505a\u5230\u4e24\u4eba\u6240\u62a5\u6570\u4e4b\u548c\u4e3a 9.
123\u00f7 9\uff1d 13\u2026\u2026 6.
\u4f60\u7b2c\u4e00\u6b21\u62a5\u6570 6.\u4ee5\u540e\uff0c\u5bf9\u65b9\u62a5\u6570\u540e\uff0c\u4f60\u518d\u62a5\u6570\uff0c\u4f7f\u4e00\u8f6e\u4e2d\u4e24\u4eba\u62a5\u7684\u6570\u548c\u4e3a 9\uff0c\u4f60\u5c31\u80fd\u5728 13\u8f6e\u540e\u8fbe\u5230 123.
16.4
17.\u753226\u53c82/3\u5929\uff0c\u4e5940\u5929
18.21
19.14\u53c81/3
20.10
21.\u7532\u3001\u4e59\u4e24\u5730\u76f8\u8ddd540\u5343\u7c73\uff0c\u539f\u6765\u706b\u8f66\u7684\u901f\u5ea6\u4e3a\u6bcf\u5c0f\u65f690\u5343\u7c73\u3002
22.750
23.384
24.600
25.\u4e00\u73ed48\u4eba\uff0c\u4e8c\u73ed42\u4eba
26.15
27.82
28.312
29.\u6700\u5c115\u4e2a\uff0c\u6700\u591a7\u4e2a
30.784
1. \u6709\u7532\u4e59\u4e24\u79cd\u7cd6\u6c34\uff0c\u7532\u542b\u7cd6270\u514b\uff0c\u542b\u6c3430\u514b\uff0c\u4e59\u542b\u7cd6400\u514b\uff0c\u542b\u6c34100\u514b\uff0c\u73b0\u8981\u5f97\u5230\u6d53\u5ea6\u662f82.5%\u7684\u7cd6\u6c34100\u514b\uff0c\u95ee\u6bcf\u79cd\u5e94\u53d6\u591a\u5c11\u514b\uff1f
2. \u4e00\u4e2a\u5bb9\u5668\u91cc\u88c5\u670910\u5347\u7eaf\u9152\u7cbe,\u5012\u51fa1\u5347\u540e,\u7528\u6c34\u52a0\u6ee1,\u518d\u5012\u51fa1\u5347,\u7528\u6c34\u52a0\u6ee1,\u518d\u5012\u51fa1\u5347,\u7528\u6c34\u52a0\u6ee1,\u8fd9\u65f6\u5bb9\u5668\u5185\u7684\u9152\u7cbe\u6eb6
\u6db2\u7684\u6d53\u5ea6\u662f?
3. \u6709\u82e5\u5e72\u5343\u514b4%\u7684\u76d0\u6c34,\u84b8\u53d1\u4e86\u4e00\u4e9b\u6c34\u5206\u540e\u53d8\u6210\u4e8610%\u7684\u76d0\u6c34,\u5728\u52a0300\u514b4%\u7684\u76d0\u6c34,\u6df7\u5408\u540e\u53d8\u62106.4%\u7684\u76d0\u6c34,\u95ee\u6700\u521d\u7684\u76d0\u6c34\u662f\u591a\u5c11\u5343\u514b?
4.\u5df2\u77e5\u76d0\u6c34\u82e5\u5e72\u514b\uff0c\u7b2c\u4e00\u6b21\u52a0\u5165\u4e00\u5b9a\u91cf\u7684\u6c34\u540e\uff0c\u76d0\u6c34\u6d53\u5ea6\u53d8\u4e3a3\uff05\uff0c\u7b2c\u4e8c\u6b21\u52a0\u5165\u540c\u6837\u591a\u7684\u6c34\u540e\uff0c\u76d0\u6c34\u6d53\u5ea6\u53d8\u4e3a2\uff05\u3002\u6c42\u7b2c\u4e09\u6b21\u52a0\u5165\u540c\u6837\u591a\u7684\u6c34\u540e\u76d0\u6c34\u7684\u6d53\u5ea6\u3002
5.\u6709A\u3001B\u3001C\u4e09\u79cd\u76d0\u6c34\uff0c\u6309A\u4e0eB\u7684\u6570\u91cf\u4e4b\u6bd4\u4e3a2\uff1a1\u6df7\u5408\uff0c\u5f97\u5230\u6d53\u5ea6\u4e3a13\uff05\u7684\u76d0\u6c34\uff1b\u6309A\u4e0eB\u7684\u6570\u91cf\u4e4b\u6bd4\u4e3a1\uff1a2\u6df7\u5408\uff0c\u5f97\u5230\u6d53\u5ea6\u4e3a14\uff05\u7684\u76d0\u6c34\uff1b\u6309A\u3001B\u3001C\u7684\u6570\u91cf\u4e4b\u6bd4\u4e3a1\uff1a1\uff1a3\u6df7\u5408\uff0c\u5f97\u5230\u6d53\u5ea6\u4e3a10.2\uff05\u7684\u76d0\u6c34\uff0c\u95ee\u76d0\u6c34C\u7684\u6d53\u5ea6\u662f\u591a\u5c11\uff1f
那么,最初的盐分含量就是4%x,
蒸发后,盐分含量不变,而浓度变为10%,那么增发后的盐水质量是
(4%x)/(10%)
;
加入300g盐水后,盐水质量变成
(4%x)/(10%)
+300,由浓度为6.4%得到:
加入300g盐水后,盐分含量为6.4%[ (4%x)/(10%) + 300] ;
而加入300g盐水后,另一个盐分含量表达式为:4%x+300*4%;
因此得到等式 6.4%[ (4%x)/(10%) + 300] = 4%x+300*4%
解这个等式,得到x=500
那么,最初盐水共500g
设最初的盐水为x克,蒸发水分y克,
4%*x/(x-y)=10%
(4%*x+300*4%)/(x-y+300)=6.4%
解得y=300, x=500
最初的盐水是500克
解设原来有盐水x克
4%x+300×4%=6.4%×(4%x÷10%+300)
4%x+12=6.4%×(0.4x+300)
4%x+12=2.56%x+19.2
1.44%x=7.2
x=500