JAMB Mathematics 2023 Paper

Concept:Percentage error measures how far a measured value is from the true value, expressed as a percentage of the true value.Explanation:The formula for percent error is:$$\text{Percent error} = \frac{\text{Measured value} - \text{Actual value}}{\text{Actual value}} \times 100\%$$Here, the student measured $18\ \text{mL}$ while the teacher’s actual value is $18.4\ \text{mL}$.Find the absolute error by subtracting the student’s reading from the actual value:$$\text{Error} = 18.4 - 18 = 0.4\ \text{mL}$$Now substitute the error and actual value into the formula:$$\text{Percent error} = \frac{0.4}{18.4} \times 100\%$$Simplify the fraction:$$\frac{0.4}{18.4} = \frac{4}{184} = \frac{1}{46}$$Then multiply by $100\%$:$$\frac{1}{46} \times 100\% \approx 2.17\%$$Answer:The student’s percent error is $2.17\%$, which corresponds to option A.