The swimming lane of a swimming pool is 50 meters long, and Xiaojun swam 3 times back and forth, how many meters did he swim in total?
一个游泳池的泳道长50米，小军游3个来回，一共游了多少米．
<gadget id="calculator">50 * 2 * 3</gadget>
<output>300</output>

<result>300</result>