Answer :
First we need to convert yard to miles
3520yards÷1760yards/mile=2 miles
From there we know:
Alex walked 1 mile for 15 mins and Sally walked 2mile in 24 mins
We need to convert these mileages to miles per hour
1mile/15mins*60mins/hour=4miles /hour
2mile/24mins*60mins/hour=5miles per hour
Alex walks at 4 miles per hour and Sally at 5 miles per hour
Sally walks 1 mile per hour faster than Alex
3520yards÷1760yards/mile=2 miles
From there we know:
Alex walked 1 mile for 15 mins and Sally walked 2mile in 24 mins
We need to convert these mileages to miles per hour
1mile/15mins*60mins/hour=4miles /hour
2mile/24mins*60mins/hour=5miles per hour
Alex walks at 4 miles per hour and Sally at 5 miles per hour
Sally walks 1 mile per hour faster than Alex