The school held a table tennis match. There are 12 participants in the fourth grade, which is equivalent to (3/4) the number of participants in the fifth grade, and the number of participants in the fifth grade is equivalent to (4/5) in the sixth grade. How many people in the sixth grade participate in the competition?
学校举行乒乓球比赛．四年级有12人参加，相当于五年级参加人数的(3/4)，五年级参加的人数相当于六年级的(4/5)．六年级有多少人参加比赛？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">12 / (3/4) / (4/5)</gadget>
<output>20</output>

<result>20</result>