Final answer:
The mason's novice apprentice would take 30 hours to construct the wall alone, based on the combined rates of work when all three together can complete it in 5 hours.
Step-by-step explanation:
To answer how long it would take the mason's novice apprentice to do the job if all three can complete the wall in 5 hours, first we need to establish the rate at which they work when combined. To calculate the working rates, we must understand that the mason, the experienced apprentice, and the novice apprentice all contribute to the work done.
The combined work formula can be written as 1/W = 1/M + 1/A + 1/N, where M is the time it takes for the mason to complete the work, A for the apprentice, and N for the novice. Given that the mason can construct the wall in 10 hours (1/M = 1/10), and the experienced apprentice in 15 hours (1/A = 1/15), if they can complete the work together in 5 hours (1/W = 1/5), we solve for the unknown rate of the novice apprentice (1/N).
By substituting the known values into the equation, we obtain:
1/5 = 1/10 + 1/15 + 1/N.
Adding the rates of the mason and the experienced apprentice, we have:
1/5 = (3/30) + (2/30) + 1/N,
1/5 = 5/30 + 1/N,
1/5 - 5/30 = 1/N,
6/30 - 5/30 = 1/N,
1/30 = 1/N.
This indicates that the novice apprentice alone would take 30 hours to construct the wall. The work rate for the novice is one thirtieth of a wall per hour.