There are 800 students in the sixth grade of the Experimental Primary School. According to the plan, each boy will plant 20 trees, and each girl will plant 15 trees. During the actual tree planting, (1/4) of the boys will stay in the school for cleaning, and (3/4) will participate in the tree planting. All the students who participated in the tree planting completed the tree planting task as planned. How many trees were actually planted?
实验小学六年级有800名学生，按计划每个男生植树20棵，每个女生植树15棵，实际植树时男生人数的(1/4)留在学校打扫除，(3/4)参加植树．参加植树的学生都能按计划完成了植树任务．实际共植树多少棵？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">20 * (3/4) * 800</gadget>
<output>12_000</output>

<result>12_000</result>