SOLUTION: How many mg of a metal containing 45% nickel must be combined with 6 mg of pure nickel to form an alloy containing 78% nickel?

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: How many mg of a metal containing 45% nickel must be combined with 6 mg of pure nickel to form an alloy containing 78% nickel?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 533133: How many mg of a metal containing 45% nickel must be combined with 6 mg of pure nickel to form an alloy containing 78% nickel?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +x+ = mg of a metal containing 45% nickel
+.45x+ = mg of pure nickel in 45% alloy
----------
+%28+.45x+%2B+6+%29+%2F+%28+x+%2B+6+%29+=+.78+
+.45x+%2B+6+=+.78%2A%28+x+%2B+6+%29+
+.45x+%2B+6+=+.78x+%2B+4.68+
+.78x+-+.45x+=+6+-+4.68+
+.33x+=+1.32+
+x+=+4+
4 mg of 45% nickel metal must be added
check:
+%28+.45%2A4+%2B+6+%29+%2F+%28+4+%2B+6+%29+=+.78+
+%28+1.8+%2B+6+%29+%2F+10+=+.78+
+7.8+=+.78%2A10+
+7.8+=+7.8+
OK