Percentages are ratios of an amount compared to 100. The percent change of an old to new value is equal to 100% x \({ new - old \over old }\).
Charlie loaned Bob $1,000 at an annual interest rate of 9%. If no payments are made, what is the interest owed on this loan at the end of the first year?
| $15 | |
| $10 | |
| $90 | |
| $9 |