There is a document of 5,700 characters. Due to time constraints, two typists A and B are arranged to start typing at the same time. A enters 100 words per minute, and B enters 90 words per minute. How many words did A enter when this document is finished?
有一份5700个字的文件，由于时间紧急，安排甲、乙两名打字员同时开始录入．甲每分录入100字，乙每分录入90个字，录完这份文件时，甲录入了多少个字？
<gadget id="calculator">100 + 90</gadget>
<output>190</output>

<gadget id="calculator">5_700 / 190</gadget>
<output>30</output>

<gadget id="calculator">30 * 100</gadget>
<output>3_000</output>

<result>3_000</result>