Multiple choice

30 men can complete a job in 40 days. However, after 24 days some men out of the assigned 30 left the job. The remaining people took another 40 days to complete the job. The number of men who left the job is

  1. 24

  2. 18

  3. 12

  4. 6
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total work is 30 men * 40 days = 1200 man-days. In 24 days, 30 men did 30 * 24 = 720 man-days of work, leaving 480 man-days. Since the remaining work took 40 days, the number of men left is 480 / 40 = 12 men. Thus, 30 - 12 = 18 men left the job.

AI explanation

The total work is 30 men multiplied by 40 days, which equals 1200 man-days. The work done in the first 24 days by 30 men is 720 man-days, leaving 480 man-days of work. If the remaining men took 40 days to complete this, their number was 480 divided by 40, yielding 12 men. Thus, the number of men who left the job is 30 minus 12, which equals 18.

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