A job, originally planned to take 4 hours to complete, in order to pursue the perfect details, now 5 hours to complete, work efficiency than the original 1. A job, originally planned to take 4 hours to complete, in order to pursue the perfect details, now 5 hours to complete, work efficiency than the original reduced by several percent?

A job, originally planned to take 4 hours to complete, in order to pursue the perfect details, now 5 hours to complete, work efficiency than the original 1. A job, originally planned to take 4 hours to complete, in order to pursue the perfect details, now 5 hours to complete, work efficiency than the original reduced by several percent?

If the workload of this work is 1 and it takes 4 hours to complete, then the efficiency per hour = 1 / 4 = 25%
Now it takes five hours. It's 1 / 5 = 20%
Work efficiency = (20% - 25%) / 25% = - 20%, reduced by 20%
It's a primary school student, isn't it