Explanation: we know that she can run 100 meters per 30 seconds. the question is asking in terms of minutes, however. we have to convert the seconds into minutes. How many minutes is 30 seconds? well, 60 seconds are in a minute so 30 seconds are in half a minute. 30 seconds = .5 minutes.
Now, we have to find how many meters she runs per minute. this means how many meters she runs in one minute. we create a proportion:
100 meters/ .5 minutes = x meters / 1 minute
we cross multiply to get 100 = .5x
then, we simplify by dividing each side by .5 which equals
