Everyone wants success and to learn the key to success, Everyone wants to have a happy life, do meaningful work, enjoy a career and achieve financial independence. The above mentioned statement means attention on the details or a project rather than on the end product. Whenever we begin working on a specific task, many people will think about the end result and get distracted by the results the task may be able to produce, but the key success is to focus on the work at hand. I don't think that the advice offered in the statement is worth following. The central problem with this advice is that focusing attention completely on that task at hand without reference to how that task is related to the end product would be virtually impossible to do. The reason for this is simple. Without some reference to a goal we would have no idea of what task to perform in the first place. As a result, the various tasks we engage in would be somewhat random and in turn no matter how diligent and careful we were in performing them the likelihood of producing worthwhile or successful end products would be minimal. Some people say that focusing too much on results allows one to skip certain aspects in the process or make mistakes along the line. But this is not true. If any aspect in the process of skipped to achieve better results, than clearly that aspect was not needed to begin with. So to ensure good results one should take a balance approach to take the task at hand. By a balanced approach, I mean paying attention to both desired result and the specific task that are required to achieve it. Moreover, the order of the tasks is determined with reference to this result. So in my view, following this advice is more likely to produce unsuccessful results than successful ones.

Let, x units of 12% acid needs to be mixed with.

According to question

x $\times$ 12% +400 $\times$ 6% = (400+x) $\times$ 10%

$$\begin{gathered} =\frac{12x}{100}+\frac{400\times 6}{100}=\frac{(400+x)\times 10\%}{100} \\ =12x+2400=4000+10x \\ [Multiplying both sides by 100] \\ =2x=1600 \\ \therefore x=\frac{1600}{2}=800 \\ Answer: 800 unites of 12\% acid needs to be mixed. \end{gathered}$$