Answer:
Step-by-step explanation:
If the bricklayer can construct the wall in its entirety in 3 hours, then he can get 1/3 of the job done in an hour.
If the apprentice can get the whole job done in 5 hours, then he can get 1/5 of the job done in an hour. If they both work together on said job, the equation is
and now we solve for x. Multiply everything by the LCM to get rid of the fractions. That would be 15x:
and doing that gives us
5x + 3x = 15 and
8x = 15 so
x = 1.875 hours which is 1 7/8 hours which is also 1 hour and 52 1/2 minutes.