Teacher Zhang rides a variable speed bicycle for exercise. There are two front gears and two rear gears. The front gears are 48 teeth and 36 teeth respectively, and the rear gears are 24 teeth and 12 teeth respectively. Where does the chain tune fit? If the diameter of the wheel is 50 centimeters, how many meters does the front geared car travel in one circle?
张老师骑一辆变速自行车锻炼，有两个前齿轮和两个后齿轮，前齿轮分别是48齿和36齿，后齿轮分别是24齿和12齿，回来时正遇顶风，张老师应将链条调在哪里合适？如果车轮直径是50厘米，那么蹬一圈前齿轮车子向前走多少米？
<gadget id="calculator">36 / 24</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(3/2) * 3.14 * (1/2)</gadget>
<output>2.355</output>

<result>2.355</result>