ship travels 200 kilometers from port A to port B in the morning and 250 kilometers in the afternoon, and there is still (1/10) of the whole journey left. How many kilometers is the voyage between ports A and B?
一艘轮船从甲港到乙港，上午行了200千米，下午行了250千米，还剩下全程的(1/10)，甲乙港之间的航程有多少千米．
<gadget id="calculator">200 + 250</gadget>
<output>450</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">450 / (9/10)</gadget>
<output>500</output>

<result>500</result>