car travels from place A to place B at a distance of 80 kilometers at a speed of 50 kilometers per hour. The gasoline you bring can last up to 3 hours. If you don’t refuel on the way, in order to ensure that you can return to the starting point, you should drive back as far as the maximum number of kilometers you drive.
一辆汽车以每小时50千米的速度，从相距80千米的甲地开往乙地．所带的汽油最多可以行3小时，在途中不加油的情况下，为保证返回出发地，最多开出多少千米，就应往回行驶了．
<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">50 * (3/2)</gadget>
<output>75</output>

<result>75</result>