Answer:
7.5 hours the second crew will take to finish cleaning the building
Step-by-step explanation:
Given that it takes 8 hours for one crew to clean an office building. It takes a second crew 10 hours to clean the same building.
If the first crew works 2 hours and leaves, 25% of cleaning work is completed
REmaining work is 75%
Second crew takes 10 hours for 100% cleaning
Hence for 75% cleaning it would take
[tex]10*0.75\\=7.5[/tex]
7.5 hours the second crew will take to finish cleaning the building
