高中数学题,关于概率与统计的,急需答案!

题目

高中数学题,关于概率与统计的,急需答案!
A real estate company with 8 employees in their north office and 6 in their south office is planning to lay off 7 employees. If they decide to lay off 4 employees from the north office and 3 from the south office, in how many ways can this be done?
a) 12 ways b) 48 ways c) 1400 ways d) none of these

答案

north:8中取4,
south 6中取3,
用组合数,相乘,得1400
选C