Question

A work can be completed by $40$ workers in $40$ days. If $5$ workers leave every $10$ days, in how many days work will be completed?

• A. $55.66$
• B. $56.44$
• C. $56.66$
• D. $54.66$

Answer 1

Answer: (C)

$56.66$

A work can be completed by $40$ workers in $40$ days.

Number of days required to complete the work by one worker $=40\times 40=1600$ mandays(days per worker)

Day----mandays----total mandays

10 400 400

20 350 750

30 300 1050

40 250 1300

50 200 1500

:

After 50 days:

1500 man-hrs have been accumulated, 15 men are on the job.

Then, 100 more man-days required

$15d=100$

$\therefore$ $d=100/15=6.66$

$\therefore$ Total no. of days required $=50+6.66=56.66$ days.

Hence, option C is correct.