There is a batch of rice in the grain depot, and after it was shipped out (2/5), another 45 tons was shipped in. At this time, the rice in the library is 3 tons more than 75% of the original rice. How many tons of original rice in Curry?
粮库现有一批大米，运出(2/5)后，又运来45吨．这时库里的大米比原来大米的75%还多3吨．库里原有大米多少吨？
<gadget id="calculator">45 - 3</gadget>
<output>42</output>

<gadget id="calculator">75 / 100</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">2 / 5</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">(3/4) - (3/5)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">42 / (3/20)</gadget>
<output>280</output>

<result>280</result>