Speed is measured as distance per unit time. Some examples of speed measurements: Miles per hour, Kilometers per hour, Meters per second, feet per minute.
To get a speed, divide the distance covered by the time it took to cover that distance.
In this example, you have a mixture of 3 unit times: hours, minutes, seconds. One way to solve this problem is to convert the time so that it is all one unit. I suggest you convert to hours: Convert the 22 seconds to minutes, add that result to the 36 minutes, and then convert the sum to hours. Next, add that to the number of hours.
Then, when you divide the marathon distance by the hours, you have your answer in km / hour.
(My policy is to not answer homework questions with something you can copy and paste. I'd rather give you some guidance in how to solve the problem. In the future, you may want to solve problems like this in real life. But, the numbers will be different.)