The agricultural machinery factory produces diesel engines. It originally planned to produce 60 units per day, but it could be completed within the scheduled time. The actual production of 90 units per day was completed 6 days ahead of schedule. How many diesel engines are there in this batch?
农机厂生产柴油机，原计划每天生产60台，可以在预定时间内完成，实际每天生产90台，结果提前6天完成，这批柴油机有多少台？
<gadget id="calculator">1 / 60</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">1 / 90</gadget>
<output>1/90 = around 0.011111</output>

<gadget id="calculator">(1/60) - (1/90)</gadget>
<output>1/180 = around 0.005556</output>

<gadget id="calculator">6 / (1/180)</gadget>
<output>1_080</output>

<result>1_080</result>