Class 3 (1) students go to work, among them (1/5) pull weeds, the number of students who water trees is exactly twice that of students who pull weeds, and the rest of the students go to water flowers, and the students who water flowers account for a fraction of the whole class Several?
三(一)班同学去劳动，其中(1/5)拔草，浇树的同学正好是拔草同学的2倍，其余的同学去浇花，浇花的同学占全班人数的几分之几？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) * 2</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (1/5) - (2/5)</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>