A company undertakes a project to be completed in 40 days with 80 workers. After 10 days, due to a shortage, only 60 workers remain. How many additional workers must be hired after 20 more days to complete the project on time?
Show answer & explanation
Correct answer: C
Explanation
Total work = 80 × 40 = 3200 man-days
Work done in the first 10 days = 80 × 10 = 800 man-days
Work done by 60 workers in the next 20 days = 60 × 20
= 1200 man-days
Total work done in 30 days = 800 + 1200 = 2000 man-days
Remaining work = 3200 − 2000 = 1200 man-days
Remaining time = 10 days
Therefore, required workers = 1200/10 = 120 workers
There are already 60 workers.
Additional workers = 120 − 60 = 60