A sprinter ran 3 times back and forth on a straight runway, and ran a total of 900 meters. How long is this straight runway in meters?
短跑选手在一段直跑道上跑了3个来回，共跑了900米，这段直跑道长多少米？
<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">900 / 6</gadget>
<output>150</output>

<result>150</result>