The number A is (2/5), the number B is the reciprocal of the number A, and the number C is the product of the numbers A and B, then the number C = how much.
甲数是(2/5)，乙数是甲数的倒数，丙数是甲、乙两数的积，则丙数=多少．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">(2/5) * (5/2)</gadget>
<output>1</output>

<result>1</result>