It is known that ba=0.75, a/b=(1/4), then (1/2)(a+b)=how many.
已知b-a=0.75，a/b=(1/4)，那么(1/2)(a+b)=多少．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) + 1</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">(1/2) * (5/4)</gadget>
<output>5/8 = around 0.625</output>

<result>5/8 = around 0.625</result>