A factory produces a batch of chemical fertilizers. Workshop A takes 12 days to complete, and workshop B takes 15 days to complete. The two workshops jointly produce 7 days, and the task is overfulfilled by 60 tons. How many tons of fertilizer are planned to be produced?
某工厂生产一批化肥，甲车间要12天完成，乙车间要15天完成，两个车间共同生产7天，超额完成任务60吨，计划生产化肥多少吨？
<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/12) + (1/15)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">(3/20) * 7</gadget>
<output>21/20 = around 1.05</output>

<gadget id="calculator">(21/20) - 1</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">60 / (1/20)</gadget>
<output>1_200</output>

<result>1_200</result>