An alloy contains tin and copper in the ratio of 4:5 . If tin has 20% impurity and copper has 58% , what is the avg impurity percentage ?	Choose the correct option.
A) 20%	B) 41.1%	C) 35%	D) 38%	E) 43.1%
Total of 9 kgs.   Tin = 4Kgs; copper = 5Kgs   Impurity in tin = 0.2 * 4= 
<gadget id="calculator">0.2 * 4</gadget>
<output>0.8</output>
0.8   Impurity in copper= 0.58 * 5= 
<gadget id="calculator">0.58 * 5</gadget>
<output>2.9</output>
2.9   Avg impurity= (0.8 + 2.9)/(4+5) = 3.7/9 = ~41%   ANSWER:41.1%
<result>B</result>
An alloy contains tin and copper in the ratio of 4:5 . If tin has 20% impurity and copper has 58% , what is the avg impurity percentage ?