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

### Instruction:
 蒂姆有30只蟾蜍。吉姆比蒂姆多20只蟾蜍。莎拉比吉姆多两倍的蟾蜍。莎拉有多少只蟾蜍？


### Response:
 吉姆：20+30=<<20+30=50>>50只蟾蜍
莎拉：50*2=<<50*2=100>>100只蟾蜍