A cylindrical oil barrel has a bottom diameter of 60cm and a height of 1m. After pouring out 40% of the oil in the barrel, how high is the remaining oil in the barrel?
一个圆柱形油桶底面直径是60cm，高是1m，倒出这桶油的40%后，油桶内剩下的油高多少厘来？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 * 100 * (3/5)</gadget>
<output>60</output>

<result>60</result>