There are 2 bars of copper-nickel alloy. One bar has 2 parts of copper to 5 parts of nickel. The other has 3 parts of copper to 5 parts of nickel. If both bars are melted together to get a 20 kg bar with the final copper to nickel ratio of 5:11. What was the weight of the first bar?  Choose the correct choice.
A) 1 kg B) 4 kg C) 6 kg D) 14 kg E) 16 kg
In the 20 KG bar,   Copper constitutes 5/16*20 = 25/4 of the mixture   Nickel constitutes 11/16*20 = 55/4 of the mixture   Now,   Let C/N ratio in Bar 1 of the solution be 2a : 5a   Let C/N ratio in Bar 2 of the solution be 3b : 5b   Therefore,   2a+3b = 25/4 and   5a+5b = 55/4   Solving for the above you get,   b= 3/4 and a=2   Now weight of the first bar = 2a+5a = 7*2 2 +5= 
<gadget id="calculator">2 +5</gadget>
<output>7</output>
7*2= 
<gadget id="calculator">7*2</gadget>
<output>14</output>
14   ANSWER:14 kg
<result>D</result>
There are 2 bars of copper-nickel alloy. One bar has 2 parts of copper to 5 parts of nickel. The other has 3 parts of copper to 5 parts of nickel. If both bars are melted together to get a 20 kg bar with the final copper to nickel ratio of 5:11. What was the weight of the first bar?