Sixty-five percent of a number is 21 less than four-fifths of that number. What is the number?
Answer
Answer (as printed):
Explanation
Let the number be $x$. Then, $\frac{4}{5}x-(65\% \text{ of } x)=21 \Leftrightarrow \frac{4}{5}x-\frac{65}{100}x=21 \Leftrightarrow 15x=2100 \Leftrightarrow x=140$.
Explanation as extracted from the printed page; notation may be imperfect.