If a certain number is increased by 50%, it becomes 75. What is this number?
某数增加它的50%后是75，这个数是多少．
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 + (1/2)</gadget>
<output>3/2 = around 1.5</output>

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

<result>50</result>