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

### Instruction:
 布伦达每天烤20个蛋糕。她连续这样做了9天，然后卖掉了一半的蛋糕。布伦达还剩下多少个蛋糕？


### Response:
 经过9天，布伦达烤了20 * 9 = <<20*9=180>>180个蛋糕。
卖掉一半后，剩下的蛋糕总数是180个蛋糕 / 2 = <<180/2=90>>90个蛋糕。