A car drives from Sanming to Xiamen. After driving for 90 minutes, the ratio of the distance traveled to the remaining distance is 3:5. If it travels another 42km, it is exactly half of the journey. How long is the road from Sanming to Xiamen? rice?
一辆汽车从三明开往厦门，开出90分钟后，已经行的路程和剩下的路程比是3：5，如果再行42km，正好行了全程的一半，三明到厦门的公路长多少千米？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">3 + 5</gadget>
<output>8</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">(1/2) - (3/8)</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">42 / (1/8)</gadget>
<output>336</output>

<result>336</result>