Answer:
6 students are served per hour.
45.12% probability a student waits less than 6 minutes.
Step-by-step explanation:
Exponential distribution:
The exponential probability distribution, with mean m, is described by the following equation:

In which
is the decay parameter.
The probability that x is lower or equal to a is given by:

Which has the following solution:

mean of 10 minutes.
This means that
, so 
How many students are served per hour?
One student is served each 10 minutes, on average
An hour has 60 minutes
60/10 = 6
6 students are served per hour.
Calculate the probability a student waits less than 6 minutes.

45.12% probability a student waits less than 6 minutes.