Amaster painter can paint 110 square yards of surface area with a roller in 1 hour, while his apprentice can paint 85 square feet of surface area per hour with a brush . together they are painting a building with a surface area of 5100 square feet. after painting for 4. 1/4 hours , the master painter lets the apprentice finnish the job. approximately how long will it take the apprentice to complete the project using a brush

The apprentice needs 6.25 hours to complete the job using the brush

Given, A master painter can paint 110 square yards of surface area with a roller in 1 hour

We know that 1 yard = 3 feet

While his apprentice can paint 85 square feet of surface area per hour with a brush

Together they are painting a building with a surface area of 5100 square feet.

After painting for hours , the master painter lets the apprentice Finish the job.  

Now, they worked for hours  

Then, area painted = area painted by master + area painted by apprentice

Now, the remaining area to be painted = total area – painted area  

Area to be painted = 5100 – 4568.75 = 531.25

So, apprentice has to paint 531.25 square feet alone.

Hence, the apprentice needs 6.25 hours to complete the job