A Printing Service workshop accepts as many as 15 printers to be serviced. There are two types of printers, which is a new model printer (laser) and the old model printer (inkjet). If the service receives repair requests, there are 10 new printers(laser) and 5 old printers(inkjet). A new employee at the service was assigned to repair 5 printers.
a. What is the chance that no new model printer will be repaired by a new employee?
b. What is the chance that at least 2 new printer models will be repaired by a new employee?
c. What is the average number of new printer models repaired by the new employee?
d. What is the variance of the number of new printer models repaired by the new employee?