For a barrel of gasoline, first use up 20% of the total amount, and then use up the rest (1/2). At this time, there are 60 kilograms left in the gasoline barrel. How many kilograms does this barrel of gasoline originally weigh?
一桶汽油，先用去总数的20%，再用去剩下的(1/2)，这时汽油桶里还剩60千克，这桶汽油原来重多少千克？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">60 / (1/2) / (4/5)</gadget>
<output>150</output>

<result>150</result>