Teacher Wang inputs a manuscript on the computer, works for 4 hours in the morning, and inputs 15,000 words. According to this calculation, it will take another 16 hours to complete the task. How many words are there in this manuscript?
王老师在电脑上输入一部书稿，上午工作4小时，输入15000字，照这样计算，还需16小时才能完成任务．这部书稿的字数有多少？
<gadget id="calculator">15_000 / 4</gadget>
<output>3_750</output>

<gadget id="calculator">4 + 16</gadget>
<output>20</output>

<gadget id="calculator">3_750 * 20</gadget>
<output>75_000</output>

<result>75_000</result>