Manila walked home in 30 minutes. She walks 4 miles an hour. Since 30 minutes is half an hour then its half the distance of the rate. 4/2 = 2 miles. This means home is 2 miles away.
Since her sister runs 6 miles an hour, the time it took her will be for only 2 miles. So 6 miles divided into 3 is 2. An hour divided by 3 = 20 minutes. This means her sister travels home 2 miles in 20 minutes.
