n persons do w jobs (rooms, floors) in d days: days for other persons and jobs

The same question, asked 2 times: CDS 2 2018*, CDS 1 2021. Every wording below, oldest first.

Try each one first, then open its answer.

Question 1
CDS 2 2018
45 $Twelve (12) persons can paint 10 identical rooms in 16 days. In how many days can 8 persons paint 20 such rooms ?$
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Question 2
CDS 1 2021
39 $If 20 persons can clean 20 floors in 20 days, then in how many days can 16 persons clean 16 floors?$
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