SOLUTION: When weighed in water; run loses .137 of its weight and copper .112 of its weight. If an alloy of tin and copper weighing 18 pounds loses 2.316 pounds when weighed in water, how ma

Algebra ->  Radicals -> SOLUTION: When weighed in water; run loses .137 of its weight and copper .112 of its weight. If an alloy of tin and copper weighing 18 pounds loses 2.316 pounds when weighed in water, how ma      Log On


   

Question 1114318: When weighed in water; run loses .137 of its weight and copper .112 of its weight. If an alloy of tin and copper weighing 18 pounds loses 2.316 pounds when weighed in water, how many pounds of each are there in the piece?
Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
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When weighted in water, highlight%28cross%28run%29%29 tin loses 0.137 of its weight and copper loses 0.112 of its weight.
If an alloy of tin and copper weighting 18 pounds loses 2.316 pounds when weighted in water, how many pounds of each are there in the piece?
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                Notice how I edited your post ! 


Let  x  be the amount of tin    in the alloy (in pounds), and
let  y  be the amount of copper in the alloy.


Then your first equation is

x + y = 18    pounds        (1)    (counting the total mass of the alloy)



Your second equation is

0.137x + 0.112y = 2.316     (2)    (saying that total weight loss is equal to the sums of weights loss)
                                   (it is the same as to say that the volume of the alloy is the sum of the ingredients/components volumes, 
                                    which we assume as to be granted)


Thus you have the system of two equations

     x +      y = 18        (1)
0.137x + 0.112y = 2.316     (2)


At this point, the setup is done and the rest is just a  routine arithmetic.