There is an 80-meter circular corridor. The younger brother walks on the circular corridor at a speed of 1 m/s, and the elder brother runs at a speed of 5 m/s. Now the elder brother and the younger brother are at the same point on the circular track, starting in the same direction at the same time, how many seconds did it take for the elder brother to catch up with the younger brother for the second time?
有80米环形走廊，弟弟在环形走廊上行走，速度为1米/秒，哥哥奔跑速度为5米/秒．现在哥哥和弟弟在环形跑道上的同一点，同时向同一方向出发，哥哥第二次追上弟弟的时候，用了多少秒？
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">2 / 4</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">80 * (1/2)</gadget>
<output>40</output>

<result>40</result>