7th Grade Challenging Math
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7-52) Answer
1200g
Solution: The amount of salt in the
salt water is 1800*(1-90%)=180g. The amount of water initially is 1800g. After
several days of evaporation, the ratio of salt to water is 15:85. Since the
amount of salt does not change, i.e. still 180g, therefore the amount of water
is 180*(85/15) = 1020g. Therefore, the weight of the salt water is
180+1020=1200g.
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