A worker received the task of processing a batch of parts, originally planned to process 50 parts per day, and completed it in a few days. The actual number of parts processed every day was 20% more than the original plan, and the task was completed two days ahead of schedule. How many parts are there in this batch?
某工人接到加工一批零件的任务，原计划每天加工50个，若干天完成．实际每天加工的零件个数比原计划多20%，结果提前两天完成了任务．这批零件有多少个？
<result>720</result>