Percentages are ratios of an amount compared to 100. The percent change of an old to new value is equal to 100% x \({ new - old \over old }\).
Christine scored 90% on her final exam. If each question was worth 3 points and there were 270 possible points on the exam, how many questions did Christine answer correctly?
| 94 | |
| 72 | |
| 81 | |
| 80 |