Solve Equation

Question

Joe takes 8 days to build a brick wall. sam takes 4 days to build a brick wall. How long will they take to build it together

Answer 1

Joe's work rate is 1/8 of this job per day; Sam's rate is 1/4 of the job per day.

 

Working together for t days, they complete the job:  t(1/8 + 1/4) = 1    

 

SOLVE THIS EQUATION FOR t, # if days.