A student was measuring the time it took for an experiment to take place. They found the time to be 40 seconds. However, they had started timing a few seconds after the experiment had started, and the actual time was 43 seconds. What is the percent error?

9.3%

Explanation:

Percent error = (actual value - experimental value / actual value) × 100

In this question, the actual value is 43seconds while the experimental value is 40 seconds

Hence,

%error = (43 - 40 / 43) × 100

%error = (4/43) × 100

%error = 0.093023 × 100

%error = 9.3%

the answer would be b i believe