A bottle of oil weighs (8/5) kilograms, if 25% is used, how many kilograms are used?
一瓶油重(8/5)千克，用去25%，用去多少千克？
<gadget id="calculator">8 / 5</gadget>
<output>8/5 = around 1.6</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(8/5) * (1/4)</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>