A car travels from A to B for the entire distance (2/5), and it is still 15 kilometers away from the midpoint. How many kilometers is the whole journey?
一辆汽车从甲地去乙地，行了全程的(2/5)，这时距中点还有15千米．全程有多少千米？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/2) - (2/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">15 / (1/10)</gadget>
<output>150</output>

<result>150</result>