Mingming's ribbon is 30 meters longer than Lili's. After subtracting half of Mingming's ribbon, Lili's ribbon is 10 meters longer than Mingming's. How many meters is Mingming's ribbon originally?
明明的彩带比丽丽长30米，明明的彩带减去一半后，丽丽的彩带比明明长10米，明明的彩带原来有多少米．
<gadget id="calculator">30 + 10</gadget>
<output>40</output>

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

<gadget id="calculator">1 - 1</gadget>
<output>0</output>

<gadget id="calculator">(1/2) + 0</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">40 / (1/2)</gadget>
<output>80</output>

<result>80</result>