12 men are assigned a job to be finished in 30 days. After 10 days it is…
2023
12 men are assigned a job to be finished in 30 days. After 10 days it is observed that only 1/6 of the job is completed. How many extra men are required to be deployed to do the rest of the job so that the job is completed within the scheduled time?
Answer: C. 18 — ConceptFor workers with the same constant rate, completed work equals the number of workers multiplied by the number of days and the work rate per worker.…
- A.
20
- B.
22
- C.
18
- D.
16
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Show answer & explanation
Correct answer: C
Concept
For workers with the same constant rate, completed work equals the number of workers multiplied by the number of days and the work rate per worker.
Observed progress can therefore be converted into man-days, which lets us find the total work and the workforce needed for the remaining time.
Application
The work completed in the first 10 days is 12 × 10 = 120 man-days, and this equals 1/6 of the job.
Hence the total job is 120 × 6 = 720 man-days.
The remaining work is 720 - 120 = 600 man-days, and the remaining scheduled time is 30 - 10 = 20 days.
The total workforce needed for the remaining work is 600 ÷ 20 = 30 men.
The extra workforce required is 30 - 12 = 18 men.
Cross-check
With 30 men for 20 days, the remaining capacity is 30 × 20 = 600 man-days; together with the first 120 man-days, this gives the full 720 man-days.
Result
Hence, 18 extra men are required.