Question

An experience bricklayer can construct a small wall in 3 hours. An apprentice can complete the job in 5 hours. Find how long it takes if they work together. Show work.

Answer 1

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

`(1)/(3)+(1)/(5)=(1)/(x)` and now we solve for x. Multiply everything by the LCM to get rid of the fractions. That would be 15x:

`15x((1)/(3)+(1)/(5)=(1)/(x))` 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.