The 20 kilograms poured out of a barrel of oil is exactly 5/7 of the whole barrel of oil. How many kilograms of this barrel of oil are there?
一桶油倒出的20千克恰好占全桶油的(5/7)，这桶油有多少千克．
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">20 / (5/7)</gadget>
<output>28</output>

<result>28</result>