the answer is 504 because 609/58 is 10.5 and then multiply 48 times 10.5 and you get 504
We can consider that the runner did an acceleration of 0.8 m.s during the 10 seconds of difference.
We can deduce that the runner did an acceleration of 0.08 m.s every second during this time.
Answer:
The working is done in the image attached.