The correct answer is A. 20.2 s
Step-by-step explanation:
The table shows there were three trials to measure how much time a toy car needs to move 1 meter on different surfaces. Now, to find the average time on a surface simply add the results of the three trials and divide this by number 3 (number of trials). The process to know the average time on dirt is shown below:
20 + 19.2 + 21.5 = 60.7 - Results of each of the trials
60.7 ÷ 3 = 20.2 s - Divide the total by the number of trials
This means the average time for the toy to move on dirt was 20.2s