Xiaojun and Xiaohong are running on the 200-meter track. Xiaojun runs at the starting point, and Xiaohong starts 20 meters ahead of Xiaojun. Xiaohong runs 6 meters per second, and Xiaojun runs 10 meters per second. The two run in the same direction at the same time, how many seconds does it take for Xiaojun to catch up with Xiaohong?
小军和小红在200米的跑道上跑步．小军站在起点跑，小红站在小军的前20米处起跑．小红每秒跑6米，小军每秒跑10米．两人同时同向跑，经过多少秒后小军追上小红？
<gadget id="calculator">10 - 6</gadget>
<output>4</output>

<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<result>5</result>