car runs the entire distance (2/5) on the first day, and (1/2) the remaining distance on the second day, and runs less distance (1/3) on the third day than on the first day. The remaining distance is 50 kilometers. How many kilometers is the whole journey?
一辆汽车，第一天跑完全程的(2/5)，第二天跑完剩下路程的(1/2)，第三天跑的路程比第一天少(1/3)，这时剩下的路程是50千米．全程是多少千米？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

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

<gadget id="calculator">(3/5) * (1/2)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(2/5) * (2/3)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">1 - (2/5) - (3/10) - (4/15)</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">50 / (1/30)</gadget>
<output>1_500</output>

<result>1_500</result>