University of South Carolina High School Math Contest/1993 Exam/Problem 6

Problem

After a $p%$ (Error compiling LaTeX. Unknown error_msg) price reduction, what increase does it take to restore the original price?

$\mathrm{(A) \ }p% \qquad \mathrm{(B) \ }\frac p{1-p}% \qquad \mathrm{(C) \ } (100-p)% \qquad \mathrm{(D) \ } \frac{100p}{100+p}% \qquad \mathrm{(E) \ } \frac{100p}{100-p}%$ (Error compiling LaTeX. Unknown error_msg)

Solution

Let . Thus if dollars was the original price, after the price reduction, we have dollars. We need dollars. Thus, . The percentage thus is choice .

See also

• University of South Carolina High School Math Contest/1993 Exam