<PRE><B>Question 1133067</B>
90 grams total with 9gm (10%) pure silver and 81gm (90%) pure gold.  After adding more silver, it will be 40%
so (9+x)/(90+x)=2/5, which is 40%
cross-multiply
5(9+x)+2(90+x)
45+5x=180+2x
3x=135
x=45gm silver ANSWER
the total amount of metal will be 135 gm, and now 54 of that (9+45) will be silver.
therefore, 81gm of the 135 will be gold and that is 60%.
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