There are two granaries. It is known that warehouse A holds 600 tons of grain. If 1/3 of the grain is transferred from warehouse A and 75% of the grain is transferred from warehouse B, the grain in warehouse A is twice that of warehouse B. 150 tons more, how many tons of original grain in warehouse B?
有两个粮仓，已知甲仓装粮600吨，如果从甲仓调出粮食(1/3)，从乙仓调出粮食75%后，这时甲仓的粮食比乙仓的2倍还多150吨，乙仓原有粮食多少吨？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">600 * (1/3)</gadget>
<output>200</output>

<gadget id="calculator">600 - 150 - 200</gadget>
<output>250</output>

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

<gadget id="calculator">2 * (3/4)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">2 - (3/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">250 / (1/2)</gadget>
<output>500</output>

<result>500</result>