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

### Instruction:
 马特用右手每分钟可以写10个字，用左手每分钟可以写7个字。马特用右手写5分钟比用左手多写了多少个字？


### Response:
 写字速度的差异是每分钟10个字 - 每分钟7个字 = <<10-7=3>>3个字/分钟
马特用右手写5分钟比用左手多写了3个字/分钟 x 5分钟 = <<3*5=15>>15个字。