Q18:
Departments A, B, and C have 10 employees each, and department D has 20 employees.Departments A, B, C, and D have no employees in common. A task force is to be formed by selecting 1 employee from each of departments A, B, and C and 2 employees from department D. How many different task forces are possible?
A. 19,000
B. 40,000
C. 100,000
D. 190,000
E. 400,000
答案是D，请问怎么做的啊？
3x! | 
