There are 9 baskets of tomatoes in the store, and 3 baskets of 60 kilograms are sold, accounting for just 40% of the total. How much are the original tomatoes in the store?
商店里有9筐西红柿，卖出3筐又60千克，刚好占全部的40%，问商店原有西红柿多少千克？
<gadget id="calculator">60 * 3</gadget>
<output>180</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) * 3</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">(6/5) - 1</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">180 / (1/5)</gadget>
<output>900</output>

<result>900</result>