There are 20 first-year students and 30 second-year students taking the test. The average score of the first-year students is 70 points, and the average score of the second-year students is 80 points. What is the total average score of the two grades combined?
参加考试的一年级学生有20名，二年级学生有30名，其中一年级学生的平均分为70分，二年级学生的平均分为80分．两个年级合在一起的总平均分为多少分．
<gadget id="calculator">70 * 20</gadget>
<output>1_400</output>

<gadget id="calculator">80 * 30</gadget>
<output>2_400</output>

<gadget id="calculator">1_400 + 2_400</gadget>
<output>3_800</output>

<gadget id="calculator">20 + 30</gadget>
<output>50</output>

<gadget id="calculator">3_800 / 50</gadget>
<output>76</output>

<result>76</result>