Hi a few questions i want to check my answers for here, 3. Write down an expression, evaluate the constant of proportionality, and answer the question. [Remember to work in SI units. Simplify answers to 1 d.p. only.] (a) The annual cost (C) of running a business is partly constant and partly proportional to the number of employees. If there are 20 employees, the annual cost is $400000. If there are 25 employees, the annual cost is $470000. Find the annual cost if there are 18 employees What is meant by partly constant? how would this be written. C = kN? or C = kN + c?