kind of iron ore has an iron content of 30%, how many tons of this iron ore are needed to make (3/8) tons of iron.
一种铁矿石的含铁率是30%，炼铁(3/8)吨需这种铁矿石多少吨．
<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(3/8) / (3/10)</gadget>
<output>5/4 = around 1.25</output>

<result>5/4 = around 1.25</result>