A group of workers promised to finish a job in 24 days, but 8 of them went on leave, so the rest took 30 days to finish it. How many workers were there at first?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 40
The job is the same, so the total worker-days stay the same: workers \(\times\) days before the change equals workers \(\times\) days after it.
Let there be \(N\) workers at first
\(24N=30(N-8)\)
\(24N=30N-240\), so \(6N=240\)
\(N=40\)