In one alloy there is 12% chromium while in another alloy it is 10%. 15 kg of the first alloy was melted together with 35 kg of the second one to form a third alloy. Find the percentage of chromium in the new alloy. Pick one.
A) 8.8 %
B) 9 %
C) 9.2 %
D) 8.6 %
E) 10.6 %

Rationale: "the amount of chromium in the new 15 + 35 = 50 kg alloy is 0.12 * 15 + 0.10 * 35 = 5.3 kg , so the percentage is 5.3 / 50 * 100 = 10.6 % . answer : e ."
Answer: E