Warehouse A stores 108 tons of grain, and Warehouse B stores 140 tons of grain. To make the amount of grain stored in Warehouse A three times that of Warehouse B, how many tons must be shipped from Warehouse B to Warehouse A.
甲仓库存粮108吨，乙仓库存粮140吨，要使甲仓库存粮数是乙仓库的3倍，必须从乙仓库运出多少吨放入甲仓库．
<gadget id="calculator">108 + 140</gadget>
<output>248</output>

<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">248 / 4</gadget>
<output>62</output>

<gadget id="calculator">140 - 62</gadget>
<output>78</output>

<result>78</result>