In order to celebrate the victory of the 18th National Congress of the Communist Party of China, the students in Class 1 of the fourth grade planned to make some five-star red flags with red paper and yellow paper. The students bought red paper and yellow paper, and the monitor distributed 6 red papers and 15 yellow papers to each student on average. After distributing them to 20 students, there were 145 papers left. Please calculate how many sheets of the two kinds of paper you bought in this class?
四年级一班的同学为庆祝十八大的胜利召开，准备用红纸和黄纸做一些五星红旗．同学们买来了红纸和黄纸，由班长平均发给每一个同学6张红纸、15张黄纸，发给20个同学后，还剩145张．请你计算这个班两种纸一共买了多少张？
<gadget id="calculator">6 * 20</gadget>
<output>120</output>

<gadget id="calculator">15 * 20</gadget>
<output>300</output>

<gadget id="calculator">120 + 300 + 145</gadget>
<output>565</output>

<result>565</result>