To solve this problem you must apply the proccedure shown below:
1. You have that Lina is 1000 feet behind Mona.
2. Therefore, you have:
V=d/t
Where V is the speed, d is the distance and t is the time.
3. Substitute the values into the formula shown above and solve it, as following:
V=1000 feet/10 minute
V=100 feet/minutena
4. Now, you must sum the speed of Mona:
Vt=100 feet/minute+300 feet/minute
Vt=400 feet/minute
Therefore, the answer is: 400 feet per minute.
