A student completes 18 problems per day for 5 days. If the assignment requires 90 problems, what percent is completed?

• A. 100%
• B. 75%
• C. 50%
• D. 125%

Answer: (A)

Percent completed is found by dividing the amount finished by the total amount assigned, then multiplying by 100 to convert to a percent. Here, 18 problems per day for 5 days gives 18 × 5 = 90 problems finished. The assignment requires 90 problems, so the fraction completed is 90/90 = 1, which is 100%. Therefore, the entire assignment is completed.

Other options would imply fewer or more problems than the assignment: 75% would be 0.75 × 90 = 67.5 problems, 50% would be 45 problems, and 125% would be 112.5 problems, none of which match the actual 90.