The difference between 31\% of a number and 13\% of the same number is 576. What is 17\% of that number? (Bank Recruitment, 2010)
Answer
Answer (as printed):
Explanation
Let the number be $x$. Then, 31\% of $x-13\%$ of $x=576 \Rightarrow (31-13)\%$ of $x=576 \Rightarrow 18\%$ of $x=576 \Rightarrow \frac{18}{100}x=576 \Rightarrow x=\left(\frac{576\times 100}{18}\right)=3200$. 17\% of the number $=17\%$ of $3200=\left(\frac{17}{100}\times 3200\right)=544$.
Explanation as extracted from the printed page; notation may be imperfect.