Question

A team of seven workers started a job, which can be done in 11 days. On the morning of the fourth day, several people left the team. The rest of team finished the job in 14 days. How many people left the team?

Answer 1

Hello!

To first solve this problem, let's look at how much the workers would've finished when they were still a group.

Since the job could've been originally done in 11 days with 7 people, and they only worked for 3 days (with 7 people), they originally finished 3/11 of the job.

Now, let's look at how much each person finishes of the job in one day.

Since 7 workers can finish the job in 11 days, this means that 1 worker can finish the job in 77 days, translating to that one worker does 1/77 of the job in one day.

Let's connect these ideas. There is 8/11 of the project remaining, and this was finished in 14 days. This means, every day, 4/77 of the project was finished. (8/11 divided by 14)

Since we know one worker does 1/77 of the job per day, and every day, 4/77 of the job was finished, 4 workers were on the team.

Therefore, 7-4, 3 workers left the team.

Hope this helped!