The quantity of grain stored in the two granaries of A and B is equal. If warehouse A transports 90 tons in and warehouse B transports 60 tons, then the ratio of grain between warehouses A and B is 3:1. How many tons of grain are there in each warehouse?
甲乙两个粮仓存粮数量相等，如果甲仓运进90吨，乙仓运出60吨，这时甲乙两仓粮食的比是3：1，甲乙两仓原有粮食各有多少吨？
<gadget id="calculator">60 * 3</gadget>
<output>180</output>

<gadget id="calculator">90 + 180</gadget>
<output>270</output>

<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">270 / 2</gadget>
<output>135</output>

<result>135</result>