When typing a manuscript, A can complete it in 4 hours alone, B can complete it in 2 hours alone, and two people can complete it in 2 hours, how much is the manuscript completed?
打一份稿件，甲独打4小时完成，乙独打2小时可完成，两人合打2小时，完成这份稿件的多少．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

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

<gadget id="calculator">(1/4) + (1/2)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(3/4) * 2</gadget>
<output>3/2 = around 1.5</output>

<result>3/2 = around 1.5</result>