Below is an instruction that describes a task. Write a response that appropriately completes the request in Chinese. Please answer in Chinese.

### Instruction:
 一个池塘里有40只鸭子。其中50%是麻鸭，麻鸭中有30%是雌性。有多少只雌性麻鸭？


### Response:
 有20只麻鸭，因为40 x .5 = <<40*.5=20>>20
有6只雌性麻鸭，因为20 x .3 = <<20*.3=6>>6