Lao Li is going to the wholesale market to buy some grapefruits at a price of 6 yuan and 3 kilograms, and then sell them at a price of 5 yuan and 2 kilograms. How many kilograms of grapefruit does Lao Li need to buy if he wants to make a profit of 180 yuan?
老李准备去批发市场以6元3千克的价格买进一些柚子，然后以5元2千克的价格买出．如果要获利180元，老李需要买进多少千克柚子？
<gadget id="calculator">6 / 3</gadget>
<output>2</output>

<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">(5/2) - 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">180 / (1/2)</gadget>
<output>360</output>

<result>360</result>