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

### Instruction:
 一块400克的蛋糕被分成八等份。娜塔莉吃了蛋糕的八分之一，皮埃尔吃了娜塔莉吃的两倍。皮埃尔吃了多少克的蛋糕？


### Response:
 400/8 = <<400/8=50>>50克的蛋糕是八分之一。
皮埃尔吃了50克 * 2 = <<50*2=100>>100克的蛋糕。