SOLUTION: A beaker contains 30 kilograms of salt water that is 99% water and 1% salt by weight. The water is evaporated until the beaker is 98% water and 2% salt. How many kilograms of salt

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Question 981634: A beaker contains 30 kilograms of salt water that is 99% water and 1% salt by weight. The water is evaporated until the beaker is 98% water and 2% salt. How many kilograms of salt water are in the beaker at this time? PLEASE show your work.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+.01%2A30+=+.3+ kg of salt in 1% salt solution
Let +x+ = the kg of water that is evaporated
away to give a 2% solution
+29.7+-+x+ = kg of water in the final solution
+.02%2A%28+30+-+x+%29+ = kg of salt in the final solution
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There is no salt removed, so the amount you start
with is the amount you end up with
+%28+.3+%2F+%28+30+-+x+%29%29+=+.02+
+.3+=+.02%2A%28+30-x+%29+
+.3+=+.6+-+.02x+
+.02x+=+.3+
+x+=+15+
15 kg of water is evaporated
+30+-+15+=+15+
15 kg of salt water is the final solution
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check answer:
+.02%2A15+=+.3+ kg of salt in final solution
+.3+%2F+15+=+.02+
There is 2% salt in final solution
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Another check is:
+.99%2A30+=+29.7+ kg of water to start with
+29.7+-+15+=+14.7+ kg of water in final solution
Now add the kg of salt in final solution
+14.7+%2B+.3+=+15+ kg of final solution
OK