Hello, I couldn't find an answer to the following questions on the forums - could you explain why the answer is 13?

The number of years of service of the 8 employees in a production department are 15, 10, 9, 17, 6, 4, 14, 16. What is the range in the number of years of service of the 8 employees?

a) 10

b) 11

c) 12

d) 13 --> correct

e) 14

Is the answer as simple as biggest (17) minus smallest (4) = 13?

Thanks!