Known: Number A/Number B=(1/5), the sum of A and B is 1.8. What is the number of A?
已知：甲数/乙数=(1/5)，甲、乙两数之和是1.8．甲数是多少．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">1.8 / (6/5)</gadget>
<output>1.5</output>

<gadget id="calculator">(1/5) * 1.5</gadget>
<output>0.3</output>

<result>0.3</result>