The refrigerator factory originally planned to produce 50 refrigerators per day, which can be completed within the scheduled time. The actual production is 60 units per day, and the task was completed 3 days ahead of schedule. How many refrigerators are there in total?
电冰箱厂原计划每天生产50台电冰箱可以在预定的时间里完成．实际每天生产60台，结果提前3天完成了任务．这批电冰箱共有多少台？
<gadget id="calculator">1 / 50</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">1 / 60</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">(1/50) - (1/60)</gadget>
<output>1/300 = around 0.003333</output>

<gadget id="calculator">3 / (1/300)</gadget>
<output>900</output>

<result>900</result>