Here's the question you clicked on:
chelbell409
at the pole My Bequest was only 40 feet behind Flying Lady. How long did it take My Bequest running at 54 feet per second to catch Flying Lady running at 46 feet per second?
The difference in their running speeds is 8 feet per second. This means that My Bequest is gaining 8 feet every second on Flying Lady. You can use this to figure out how long it takes to gain 40 feet.
the answer is 5 seconds i just can`t figure out how to get that
Well... 40 feet overall, divided by 8 feet every second, gets you five seconds. Does that make sense?