There are 3 bottles of alcohol solutions A, B, and C, and their mass ratio is 3:2:1. If two bottles of alcohol are mixed and then distributed into their respective bottles according to the original mass, it is called an operation. Now first perform an operation on the two bottles of alcohol A and B, then perform an operation on the two bottles of alcohol B and C, and finally perform an operation on the two bottles of alcohol C and A. After three operations, the concentrations of solutions in A and B are 67% and 61% respectively. Find the initial concentration of the acetone solution.
有甲、乙、丙3瓶酒精溶液，它们的质量比是3：2：1．如果把两瓶酒精混合后再按原来的质量分配到各自的瓶中，称为一次操作．现在先对甲、乙两瓶酒精进行一次操作，再对乙、丙两瓶酒精进行一次操作，最后对丙、甲两瓶酒精进行一次操作．三次操作后，甲、乙两瓶溶液的浓度分别是67%和61%．求最初丙溶液的浓度．
<result>0.45</result>