Mr. Vella can build a brick wall in 4 days. His apprentice can build the same wall in 6 days. After working alone for 3 days, Mr. Vella became ill and left the job for his apprentice to complete. How many days did it take the apprentice to finish the wall?
Mr. Vella can build the wall in 4 days, however only works on it for 3 days. That means that he has completed 75% of the and is leaving 25% for his apprentice.
We need to figure out how long it takes the apprentice to build 25% of a wall. We know he can build 100% of a wall in 6 days, so dividing 6 days by 4 will give us our answer.
6/4 = 3/2 = 1.5 days
It took the apprentice 1.5 days to finish the wall.