A marathon runner runs at the rate of 9 mph for the complete course. A track man runs at 12 mph. If together they run for 3 hrs.

To start, it’s important to arrange all the data provided to avoid any confusion. We will mark the marathon runner's information with a subscript of 1 and the trackman's data with a subscript of 2. Our first step will involve calculating the total time:

t₁ + t₂ = 3 hours and 1 minute

To maintain uniformity, we need to convert the minute into hours. 
1 minute (1 hour/60 minutes) = 1/60
Total time therefore equals 3 + 1/60 = 3.0167 hours

So, we have the equation: t₁ + t₂ = 3.0167 hours ----> equation 1

Next, we establish the equation for the total distance, which arises from multiplying speed by time to yield distance. Hence, we get:

9t₁ + 12t₂ = 28 miles ----> equation 2

With two unknowns and two equations, we can solve the system:

t₁ = 3.0157 - t₂
Substituting into the second equation gives us 9(3.0167 - t₂) + 12t₂ = 28
Thus, we find t₂ = 0.2832 hour, and 
t₁ = 3.0157 - 0.2832 = 2.733 hours

Consequently, the distance covered by the marathon runner would be
9*2.733 = 24.597 or roughly 24 3/5.

Result:

24 3/5

Detailed explanation: