A lamp is on sale, and its price is reduced from $80 to $50. What is the percent of decrease?
\(\frac{30}{80}\) is the fraction of decrease. Converting this to a fraction with a denominator of 100, we get the fraction;
\(\frac{37.5}{100}\)
Now we just take the numerator of the number to get the percent, which is the solution.
37.5%