A construction project was estimated to be completed in 180 days. Due to rain, only 60% of the days were productive. If the work done each productive day is constant, by what percent must daily output be increased to complete the project on time?
Show answer & explanation
Correct answer: D
Explanation
Given:
Total estimated time = 180 days
Productive days = 60%
Actual productive days = 60% × 180 = 108 days
Assuming work = 1 unit per day
Total work = 180 units
Now 180 units of work must be completed in 108 days
New daily rate = 180 / 108 = 5/3
Increase = 5/3 − 1 = 2/3
Percentage increase = (2/3) × 100 = 66.67%