An empty barrel can be filled with 4 bowls of water or 5 cups of water, now pour 1 bowl of water and 3 cups of water into the empty barrel, how much will the water level rise to the height of the empty barrel.
一个空桶装4碗水或5杯水便可装满，现将1碗水和3杯水倒入空桶，水面上升到空桶高度的多少．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) * 3</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(1/4) + (3/5)</gadget>
<output>17/20 = around 0.85</output>

<result>17/20 = around 0.85</result>