Directions
Saul scored 80% on both tests. On one, he answered 80 questions out of 100 correctly; on the other, he got 20 out of 25 questions right. 80% doesn't reflect the exact number of correct answers. It reflects the relationship of the part (the number of questions answered correctly) to the whole (total number of questions on the test).
In fact, percents are just another way to write out certain fractions and decimals. In this problem, practice changing the fraction to a decimal and the decimal to a percent.