Answer:
The three possible combinations are:
1. Running for 30 minutes, walking for 20 minutes
2. Running for 35 minutes, walking for 10 minutes
3. Running for 25 minutes, walking for 30 minutes
Step-by-step explanation:
Given that:
Elena combines running and walking on a treadmill.
Running speed = 0.2 miles/hr
Walking speed = 0.1 miles/hr
Total distance traveled = 8 miles
To find:
Three possible combinations of walking and running times.
Solution:
First of all, let us have a look at the formula for distance traveled:
Distance = Speed
Time
Here, we are given that the distance is 8 miles which is covered by both running and walking.
Let the time taken in running =
minutes
Let the time taken in walking =
minutes
Distance traveled by running =
miles
Distance traveled by walking =
miles
As per question statement:
![0.2x+0.1y = 8\\\Rightarrow 2x+y=80](https://tex.z-dn.net/?f=0.2x%2B0.1y%20%3D%208%5C%5C%5CRightarrow%202x%2By%3D80)
Now, we need to find 3 set of solutions for above equation.
The solutions can be:
x = 30, y = 20
x = 35, y = 10 and
x = 25, y = 30
So, the three possible combinations are:
1. Running for 30 minutes, walking for 20 minutes
2. Running for 35 minutes, walking for 10 minutes
3. Running for 25 minutes, walking for 30 minutes